Glass plate and window

ABSTRACT

To provide a glass plate for a window material and a window comprising the glass plate, which are less likely to be a barrier to radio transmitting/receiving in use of a radio-utilizing apparatus, and a radio communication apparatus comprising the glass plate. 
     A glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, a window comprising the glass plate, and a radio communication apparatus comprising the glass plate.

TECHNICAL FIELD

The present invention relates to a glass plate used as a window material of a vehicle, a building, etc.

BACKGROUND ART

An apparatus utilizing radio waves (hereinafter referred to as “radio-utilizing apparatus”), such as radar and a mobile phone is commonly used in a vehicle represented by an automobile or in a building. Particularly in recent years, an apparatus which employs radio waves in a high frequency band (microwaves to millimeter waves), more specifically, in a GHz frequency band, for example, in a region of from 3 to 300 GHz, has been actively developed.

Glass used as a window material of an automobile or a building is disclosed, for example, in Patent Document 1. Patent Document 1 discloses that glass which has a high visible light transmittance, which has high ultraviolet and solar shielding performance and which is visually preferable, is obtained.

PRIOR ART DOCUMENTS Patent Documents

-   Patent Document 1: JP-A-2002-348143

DISCLOSURE OF INVENTION Technical Problem

However, glass for a window material, particularly considering properties assuming use of a radio-utilizing apparatus has not been found.

It is an object of the present invention to provide a glass plate for a window material and a window, which are less likely to impair radio transmitting/receiving by a radio-utilizing apparatus in an environment where a window glass is present.

Solution to Problem

The present invention provides a glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, a window comprising the glass plate, and a radio communication apparatus comprising the glass plate.

Advantageous Effects of Invention

According to the glass plate and the window of the present invention, a radio-utilizing apparatus utilizing radio waves in a high frequency band can be used even in an automobile or in a building without any problem.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view schematically illustrating outlines of conditions to determine the wave transmittance.

FIG. 2A is a graph illustrating the electric field strength ratios of glass plates with 18 mm thickness in Comparative Example 1 and Examples 1 to 6.

FIG. 2B is a graph illustrating the electric field strength ratios of glass plates with 18 mm thickness in Comparative Example 1 and Examples 7 to 12.

FIG. 2C is a graph illustrating the electric field strength ratios of glass plates with 18 mm thickness in Comparative Example 1 and Examples 13 to 17.

FIG. 2D is a graph illustrating the electric field strength ratios of glass plates with 18 mm thickness in Comparative Example 1 and Examples 18 to 20.

FIG. 3A is a graph illustrating the approximate transmittances in Comparative Example 1 and Examples 1 to 6.

FIG. 3B is a graph illustrating the approximate transmittances in Comparative Example 1 and Examples 7 to 12.

FIG. 3C is a graph illustrating the approximate transmittances in Comparative Example 1 and Examples 13 to 17.

FIG. 3D is a graph illustrating the approximate transmittances in Comparative Example 1 and Examples 18 to 20.

FIG. 4 is a graph illustrating the measured value of the radio transmitted amount and the calculated value of the radio transmitted amount obtained by exponential approximation of the laminated glass in Comparative Example 1.

FIG. 5 is a graph illustrating the measured value of the radio transmitted amount and the calculated value of the radio transmitted amount obtained by exponential approximation of the laminated glass in each of Comparative Example 1, Example 3, Example 4, Example 11 and Example 25.

DESCRIPTION OF EMBODIMENTS

Unless otherwise specified, the following definitions of terms are applicable throughout description, drawings and claims.

“to” used to show the range of the numerical values is used to include the numerical values before and after it as the lower limit value and the upper limit value. The glass “containing substantially no” certain component means that the component is not actively added excluding an inevitably included impurity. The content of each component in the glass is represented by mol % based on oxides.

In this specification, the “radio transmittance” of the glass plate is obtained as follows.

As shown in FIG. 1 , it is assumed that a perfect conductor frame 10 having an infinite area and a finite thickness has a 90 mm square (8,100 mm²) opening 20. From a wave source 30, 60 mm apart in a vertical direction from the opening, plane waves having an electric field strength of 1 V/m are made to enter the opening vertically so that the wave front is in parallel with the opening and the polarization direction is in parallel with one side of the opening. And, the electric field strength is measured at a point (measurement point 40) 300 mm apart in a vertical direction from the center of the opening on the opposite side of the opening from the wave source. A value obtained by dividing the electric field strength measured when a glass plate sample having the same shape and the same area as the opening 20 is fitted into the opening 20, by the electric filed strength when no glass plate sample is fitted (that is, the glass plate sample is replaced with an air block having the corresponding thickness), is the electric field strength ratio of the glass plate. This electric field strength is obtained by simulation by an electromagnetic field simulator (CST Microwave Studio 2016) under the above-described conditions.

The electric field strength ratio is a proportion of the electric field strength measured through the glass plate sample to the electric field strength measured through the air, and the unit is a dimensionless number unless otherwise specified, but may be represented by percentage (%). The electric field strength ratio may be determined in accordance with the thickness, the electric constant and the dielectric loss of the glass plate, and the frequency of the incident waves. Methods for measuring the dielectric constant and the dielectric loss of the glass plate sample are known for those skilled in the art, and they are measured, for example, by cavity resonator method.

In this specification, unless otherwise specified, meanings of the following terms are as follows.

The opening is a square opening in a perfect conductor frame having an infinite area. When the radio transmittance or the electric field strength after transmission of a glass plate is measured, a glass plate sample having the same shape and the same area as the opening is fitted into the opening. The wave front of the plane waves is in parallel with the opening surface, the polarization direction of the plane waves is in parallel with one side of the opening, and the plane waves enter the opening in a perpendicular direction. The distance from the opening represents the distance along the perpendicular from the opening surface. The measurement point a certain distance apart from the opening means a point the corresponding distance apart from the opening surface along the perpendicular from the center of the opening. The wave source and the measurement point are located opposite of the opening from each other.

The thickness of the glass plate is represented by mm, the area of the opening by mm², the wavelength of the radio waves by mm, the frequency by GHz, and the electric field strength by V/m.

The glass plate of the present invention has a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, whereby the glass plate is less likely to be a barrier to transmitting/receiving by a radio-utilizing apparatus such as radar and a mobile phone. In this specification, unless otherwise specified, the radio transmittance is obtained by conducting the after-described exponential approximation. The radio transmittance is preferably at least 21%, more preferably at least 22%, more preferably at least 25%, more preferably at least 29%, more preferably at least 33%, more preferably at least 37%, more preferably at least 40%, further preferably at least 43%, particularly preferably at least 45%, even more preferably at least 48%, most preferably at least 50%.

The thickness calculation of the radio transmittance can be analytically carried out e.g. by transmission formula of plane electromagnetic waves, for example, as described in Denjidouharon Nyumon (Electromagnetic Waveguide Introduction (Masahiro Hashimoto, published by THE NIKKAN KOGYO SHIMBUN, LTD., “Chapter 2: Transmission of Electromagnetic Waves”.

The glass plate of the present invention has a radio transmittance of preferably at least 23% at a frequency of 80 GHz as calculated as 18 mm thickness, whereby the glass plate is less likely to be a barrier to transmitting/receiving by a radio-utilizing apparatus such as radar and a mobile phone. The radio transmittance is more preferably 25%, more preferably at least 26%, more preferably at least 30%, more preferably at least 35%, more preferably at least 40%, further preferably at least 44%, particularly preferably at least 48%, even more preferably at least 52%, most preferably at least 54%.

The glass plate of the present invention has a radio transmittance of preferably at least 39% at a frequency of 28 GHz as calculated as 18 mm thickness, whereby the glass plate is less likely to be a barrier to transmitting/receiving by a radio-utilizing apparatus such as radar and a mobile phone. The radio transmittance is more preferably at least 40%, more preferably at least 44%, more preferably at least 50%, more preferably at least 56%, further preferably at least 60%, particularly preferably at least 62%, even more preferably at least 65%, most preferably at least 68%.

The glass plate of the present invention has a radio transmittance of preferably at most 84% at a frequency of 100 GHz as calculated as 18 mm thickness. In order that the radio transmittance is higher than 84%, it may be necessary to excessively increase the SiO₂ component in the glass. Such glass is less likely to be melted, and the forming temperature tends to be high, whereby production of a large plate by e.g. float process, fusion process, roll out process or down draw process tends to be difficult. Further, if the radio transmittance is high, the B₂O₃ component has to be added in a large amount, whereby not only alkali elements are likely to volatilize during melting/forming, thus leading to deterioration of the glass quality, but also the average coefficient of linear expansion becomes low, whereby physical tempering tends to be difficult. Further, an increase of the B₂O₃ and SiO₂ components is likely to lead to a decrease of the Young's modulus, whereby the rigidity of the substrate decreases, and the strength at the time of use may not be secured. Further, in order to increase the radio transmittance, it is necessary to lower the content of alkali elements, which may lead to deterioration of the melting property and may remarkably deteriorate the viscosity, and further, such glass is likely to be devitrified, thus impairing the glass production. Such glass is not suitable as window glass particularly for automobiles and for building. Accordingly, the radio transmittance is more preferably at most 80%, more preferably at most 70%, more preferably at most 60%, more preferably at most 55%, further preferably at most 50%, particularly preferably at most 47%, even more preferably at most 45%, most preferably at most 43%.

The glass plate of the present invention has a radio transmittance of preferably at most 84% at a frequency of 80 GHz as calculated as 18 mm thickness. In order that the radio transmittance is higher than 84%, it may be necessary to excessively increase the SiO₂ component in the glass. Such glass is less likely to be melted, and the forming temperature tends to be high, and production of a large plate by e.g. float process, fusion process, roll-out process or down-draw process tends to be difficult. The radio transmittance is more preferably at most 80%, more preferably at most 70%, more preferably at most 61%, more preferably at most 58%, further preferably at most 55%, particularly preferably at most 52%, even more preferably at most 49%, most preferably at most 47%.

The glass plate of the present invention has a radio transmittance of preferably at most 84% at a frequency of 28 GHz as calculated as 18 mm thickness. In order that the radio transmittance is higher than 84%, it may be necessary to excessively increase the SiO₂ component in the glass. Such glass is less likely to be melted, and the forming temperature tends to be high, and production of a large plate by e.g. float process, fusion process, roll-out process or down-draw process tends to be difficult. The radio transmittance is more preferably at most 82%, more preferably at most 80%, more preferably at most 78%, more preferably at most 76%, further preferably at most 75%, particularly preferably at most 72%, even more preferably at most 68%, most preferably at most 64%.

In this specification, A represents the wavelength (unit: mm) of radio waves. The glass plate of the present invention preferably satisfies a linear approximation of y>(0.0607×x), wherein y (V/m) is the electric field strength at a measurement point 10A apart from the opening, when plane waves at a frequency of 10 GHz at an electric field strength of 1 V/m are made to enter a glass plate having a thickness of 1.2λ from a wave source 2λ apart from the opening 20, and x is a value obtained by dividing the opening area S (mm²) by λ^(2·)The measured electric field strength y which varies depending upon the opening area may be determined by simulation by an electromagnetic simulator (CST Microwave Studio 2016) employing the above conditions. The linear approximation is, as is well known to those skilled in the art, a linear approximation obtained by least squares method. The description “enter a glass plate having a thickness of 1.2λ” means that the glass plate is calculated to 1.2λthickness, and the actual thickness of the glass plate of the present invention is not necessarily 1.2λ.

The linear approximation of the glass plate being y>(0.0607×x) means that the slope of a graph of a linear function obtained by linear approximation of the relation between x and y obtained from the glass plate, is greater than the slope of the graph y=(0.0607×x). If the linear approximation is y≤(0.0607×x), that is, when the slope is at most 0.0607, functions of a radio-utilizing apparatus in a high frequency band tend to be impaired. The slope of the linear function obtained by the linear approximation is more preferably at least 0.0625, further preferably at least 0.0644. There is no particular upper limit of the slope, however, it can not be 0.0879 or greater (the value obtained when an air block is placed instead of the glass plate).

The slope of the linear function obtained by the linear approximation is preferably at most 0.0796. When it is at most 0.0796, the proportions of SiO₂ and B₂O₃ in the glass can be lowered, whereby the glass is easily produced, and further, the weather resistance and thermal expansion property of the glass can be adjusted, whereby a large glass plate suitable for preparation of a window for various applications is easily produced. The slope of the linear function obtained by the linear approximation is more preferably at most 0.0750, further preferably at most 0.0700, further preferably at most 0.0690, further preferably at most 0.0680, further preferably at most 0.0670, even more preferably at most 0.0665, most preferably at most 0.0657.

The glass plate of the present invention preferably satisfies an exponential approximation (in this specification, referred to as “exponential approximation at 100 GHz”) of y′>exp(−0.081×x′), wherein y′ is the approximate transmittance at a frequency of 100 GHz, and x′ is the thickness of the glass plate.

The exponential approximation at 100 GHz is determined as follows.

First, a curve of changes of the electric field strength ratio in accordance with the frequency x″ (GHz) is determined with respect to the glass plate to be measured as calculated as each of 12 mm, 18 mm, 24 mm, 30 mm, 36 mm and 40 mm thicknesses, the exponential approximation of the relation between x″ and the electric field strength ratio (in this specification, the exponential approximation will sometimes be referred to as “exponential approximation of the relation between the frequency and the radio transmittance”), which is taken as the radio transmittance y″. That is, a function y″=[constant 1]×e^([constant) 2]^(×x″)is approximated. The exponential approximation is, as is well known to those skilled in the art, an exponential approximation obtained by least squares method. For example, with respect to a thickness 12 mm of a glass plate (Comparative Example 1), exponential approximation of y″=0.7628e^(−0.0003x″)is obtained, and with respect to a thickness 18 mm of the same glass plate, exponential approximation of y″=0.8619e^(−0.015x″) is obtained.

This approximation formula is prepared based on analysis results by the electromagnetic simulator at from 6 to 20 GHz. It is known that due to characteristics of the electromagnetic simulator, the calculation accuracy is deteriorated as apart from the center frequency in the analysis frequency band, and particularly the accuracy in the low frequency band is remarkably deteriorated. Accordingly, values in a frequency band of at least 6 GHz are preferably employed. In this calculation, a frequency up to 20 GHz is taken as the analysis upper limit frequency, however, since the frequency dependence of the attenuation is negligibly small, the present approximation formula may be applied to a frequency of at least 20 GHz.

Accordingly, the glass plate of the present invention satisfies an exponential approximation of the relation between the frequency and the electric field strength ratio at a frequency of from 6 to 20 GHz, as calculated as 18 mm thickness, of preferably y″>0.8619e^(−0.015x)″, more preferably y″>0.85e^(−0.012x)″, further preferably y″>0.84e^(−0.010x″), particularly preferably y″>0.84e^(−0.09x″) even more preferably y″>0.84e^(−0.008x″), most preferably y″>0.84e^(−0.007x″).

Further, it is preferred that y″<0.84e^(−0.0005x″), whereby the contents of SiO₂ and B₂O₃ components in the glass can be lowered, and the glass is easily produced and further, the weather resistance, thermal expansion property, etc. of the glass can be adjusted, whereby a large glass plate suitable for preparation of a window for various applications can easily be produced. More preferably y″<0.84e^(−0.001x″), further preferably y″<0.84e^(−0.003x′), particularly preferably y″<0.84e^(−0.005x′), even more preferably y″<0.8435e^(−0.006x″), most preferably y″<0.8462e^(−0.007x″).

Now, the transmittance (approximate transmittance) at 100 GHz is calculated based on the exponential approximation formula of the relation between the frequency and the electric field strength ratio obtained with respect to each thickness, whereby a relation of the approximate transmittance y′ depending upon the thickness x′ is obtained with respect to frequency 100 GHz, and this relation is further subjected to exponential approximation, whereby the above-described “exponential approximation at frequency 100 GHz” is obtained. The thickness x′ is changed as mentioned above for the purpose of calculation to obtain the exponential approximation, however, needless to say, a specific glass plate of the present invention may haven an optional thickness.

The electric field strength ratio of radio waves which passed through a glass plate usually greatly varies whether or not the multiple of the wavelength of the radio waves agrees with the thickness of the glass plate, and is complicatedly influenced by the reflection, refraction and interference of the radio waves. Accordingly, as the frequency is continuously increased, periodic fluctuations of the electric field strength ratio with an unstable locus are observed (for example, FIG. 2A to FIG. 2D). Accordingly, discussion on whether the electric field strength ratio measured at a specific frequency is higher or lower does not necessarily essentially describe the radio transmission characteristics of the glass material. That is, even when a first glass plate transmits radio waves in a larger amount than a second glass plate at a specific frequency, it is possible that the first glass is superior in the radio transmission characteristics as a whole by macroscopic observation in a wider frequency range (FIG. 2A to FIG. 2D). Accordingly, the above-described approximation is useful. By the approximation formula, macroscopic tendency of radio transmission characteristics is described.

The exponential approximation of a certain glass plate at a frequency of 100 GHz being y′>exp(−0.081×x′) means that a graph of an exponential function obtained by subjecting the relation between x′ and y′ obtained from the glass plate to exponential approximation, is located above the graph of y′=exp(−0.081×x′). These graphs are such that y′=1 (transmittance: 100%) when x′=0 (no thickness of the glass plate), where x′ is plotted on the horizontal axis and y′ on the vertical axis. When the exponential approximation is y′≤exp(−0.081×x′), transmitting/receiving of a radio-utilizing apparatus in a high frequency band tends to be impaired. The coefficient of x′ in the exponential weather resistance, thermal expansion property etc. of the glass can be adjusted, whereby a large glass plate suitable for preparation of windows for various applications can easily be produced. The coefficient is more preferably at most −0.03, further preferably at most −0.035, particularly preferably at most −0.04, even more preferably at most −0.045, most preferably at most −0.05.

The glass plate of the present invention has an area of preferably at least 900 mm^(2·) When the glass plate has an area of at least 900 mm², the radio transmitted amount for use of a radio-utilizing apparatus can be secured, and such glass may suitably be used for building, for automobiles, etc. The area is more preferably at least 2,500 mm², more preferably at least 10,000 mm², further preferably at least 90,000 mm², particularly preferably at least 180,000 mm², even more preferably at least 360,000 mm², most preferably at least 1,120,000 mm^(2·)The upper limit of the area is not particularly limited from the viewpoint of the radio transmittance, however, a glass plate larger than 100,000,000 mm² is difficult to produce. The area is more preferably at most 56,250,000 mm², further preferably at most 25,000,000 mm², particularly preferably at most 9,000,000 mm², even more preferably at most 4,000,000 mm², most preferably at most 2,160,000 mm^(2·) When the area of the glass plate is smaller than 900 mm², application in e.g. building or automobile field may be limited, and the absolute amount of radio waves which pass through the glass plate will be small regardless of the transmittance.

The glass plate of the present invention preferably satisfies A×radio transmittance of from 0.0225 m^(2·)% to 8,400 m^(2·)%. Here, “A” is the area (m²) of the glass plate, and the radio transmittance is a radio transmittance (%) at a frequency of 100 GHz as calculated as 18 mm thickness.

When A×radio transmittance is at least 0.0225 m^(2·)%, electric field strength higher than a conventional glass plate can be obtained. If it is less than 0.0225 m^(2·)%, use as a window in a high frequency band will be more difficult. A×radio transmittance is more preferably at least 0.4 m^(2·)%, more preferably at least 4 m^(2·)%, further preferably at least 8 m^(2·)%, particularly preferably at least 16 m^(2·)%, even more preferably at least 28 m^(2·)%, most preferably at least 50 m^(2·)%. Further, by increasing A×radio transmittance, the radio transmitted amount can be increased. There is no particular upper limit of A×radio transmittance, however, it is preferably at most 8,400 m^(2·)%. If A is too large, production of the glass plate tends to be difficult. A×radio transmittance is more preferably at most 3,000 m^(2·)%, further preferably at most 800 m^(2·)%, still more preferably at most 400 m^(2·)%, particularly preferably at most 200 m^(2·)%, even more preferably at most 120 m^(2·)%, most preferably at most 80 m^(2·)%.

The glass plate of the present invention preferably satisfies a radio transmittance/t of from 0.7%/mm to 84%/mm. Here, t is the thickness (mm) of the glass plate, and the radio transmittance is a radio transmittance (%) at a frequency of 100 GHz as calculated as 18 mm thickness. When the radio transmittance/t is at least 0.7%/mm, an approximate transmittance higher than that of a conventional glass plate can be obtained. If the radio transmittance/thickness t is less than 0.7%/mm, use as a window in a high frequency band will be more difficult. The radio transmittance/t is preferably at least 1%/mm, more preferably at least 2%/mm, further preferably at least 3%/mm, particularly preferably at least 4%/mm, even more preferably at least 5%/mm, most preferably at least 5.5%/mm. By increasing the radio transmittance or by reducing the thickness, the radio transmittance/t becomes high, and the approximate transmittance can be increased. There is no particular upper limit of the radio transmittance/t, however, it is preferably at most 84%/mm. If t is too small, deflection tends to be great, and such glass can hardly be used in a large area, and glass having a high radio transmittance tends to contain the SiO₂ component in a large amount, whereby production of a glass plate tends to be difficult. Further, in order to achieve a high radio transmittance, the B₂O₃ component should be added in a large amount, whereby not only alkali elements are likely to volatilize during melting/forming, thus leading to deterioration of the glass quality, but also the average coefficient of linear expansion becomes low, and physical tempering tends to be difficult. Further, an increase of the B₂O₃ and SiO₂ components tends to lead to a decrease in the Young's modulus, whereby rigidity of the substrate may be decreased, and strength at the time of use may not be secured. Further, in order to increase the radio transmittance, it is necessary to lower the content of alkali elements, thus leading to deterioration of melting property, whereby the viscosity will remarkably be deteriorated, and further, glass is likely to be devitrified, and glass production may be impaired. Accordingly, the radio transmittance/t is preferably at most 65%/mm, more preferably at most 50%/mm, further preferably at most 40%/mm, particularly preferably at most 30%/mm, even more preferably at most 25%/mm, most preferably at most 20%/mm.

Further, considering the application, when the glass plate is used for building, the thickness of the glass plate is thick in many cases, whereby the lower limit of the radio transmittance/t is preferably lower, and it is more preferably at least 1.3%/mm, further preferably at least 1.6%/mm, particularly preferably at least 1.8%/mm, even more preferably at least 2.4%/mm, most preferably at least 3%/mm. Further, the upper limit is also preferably lower, and it is more preferably at most 25%/mm, further preferably at most 15%/mm, particularly preferably at most 11%/mm, even more preferably at most 9%/mm, most preferably at most 8%/mm.

When the glass plate is used for automobiles, the thickness of the glass plate is from 2 mm to 6 mm for example, and the lower limit of the radio transmittance/t is more preferably at least 5%/mm, further preferably at least 6%/mm, particularly preferably at least 7%/mm, even more preferably at least 7.5%/mm, most preferably at least 8%/mm. Further, the upper limit is more preferably at most 25%/mm, further preferably at most 20%/mm, particularly preferably at most 16%/mm, even more preferably at most 13%/mm, most preferably at most 12%/mm.

On the other hand, in a case where a thin glass plate of from 1 to 2 mm is used, the lower limit of the radio transmittance/t is more preferably at least 15%/mm, further preferably at least 17%/mm, particularly preferably at least 20%/mm, even more preferably at least 25%/mm, most preferably at least 30%/mm. The upper limit is more preferably at most 70%/mm, further preferably at most 60%/mm, particularly preferably at most 55%/mm, even more preferably at most 50%/mm, most preferably at most 48%/mm.

The glass plate of the present invention preferably has a specific gravity of from 2.40 to 3.00, and preferably has a Young's modulus of from 60 GPa to 100 GPa. The average coefficient of linear expansion from 50° C. to 350° C. is preferably from 50×10⁻⁷/° C. to 120×10⁻⁷/° C. When the glass plate satisfies such physical property requirements, it can be sufficiently suitably used as a window material for building, for automobiles, etc.

In order to secure the weather resistance, a certain amount or more of SiO₂ is preferably contained, and the B₂O₃ content is preferably lower. As a result, the specific gravity is preferably at least 2.40, more preferably at least 2.42, further preferably at least 2.44, still more preferably at least 2.46, particularly preferably at least 2.48, even more preferably at least 2.50, most preferably at least 2.52. The specific gravity is preferably at most 3.0, whereby the glass is less likely to be fragile, and weigh saving is achieved, and it is more preferably at most 2.90, further preferably at most 2.80, still more preferably at most 2.75, particularly preferably at most 2.70, even more preferably at most 2.65, most preferably at most 2.62.

By a high Young's modulus, the glass plate has rigidity and is more suitable for building, for automobiles, etc. The Young's modulus is more preferably at least 65 GPa, further preferably at least 70 GPa, still more preferably at least 72 GPa, particularly preferably at least 74 GPa, even more preferably at least 75 GPa, most preferably at least 76 GPa. If SiO₂ is increased so as to increase the Young's modulus, the melting property may be deteriorated. Accordingly, the Young's modulus is preferably at most 100 GPa, more preferably at most 95 GPa, further preferably at most 90 GPa, still more preferably at most 85 GPa, particularly preferably at most 82 GPa, even more preferably at most 80 GPa, most preferably at most 78 GPa.

The average coefficient of linear expansion is preferably low from the viewpoint of occurrence of thermal stress to the temperature distribution of the glass plate when used, and accordingly the average coefficient of linear expansion from 50° C. to 350° C. is preferably at most 120×10⁻⁷/° C., more preferably at most 100×10⁻⁷/° C., more preferably at most 100×10⁻⁷/° C., further preferably at most 90×10-7/° C., particularly preferably at most 80×10⁻⁷/° C., even more preferably at most 70×10⁻⁷/° C., most preferably at most 60×10-7/° C. However, if the linear expansion coefficient is too low, the thermal expansion difference with e.g. a metal sash tends to be large, thus leading to distortion and thereby breakage. Accordingly, the average coefficient of linear expansion from 50° C. to 350° C. is preferably at least 35×10-7/° C., more preferably at least 40×10⁻⁷/° C., more preferably at least 45×10-7/° C., further preferably at least 50×10⁻⁷/° C., particularly preferably at least 55×10-7/° C.

Further, for use in applications to building, for automobiles, etc., it is preferred that physical tempering is possible, and accordingly, the average coefficient of linear expansion is more preferably higher. The average coefficient of linear expansion from 50° C. to 350° C. is more preferably at least 60×10⁻⁷/° C., further preferably at least 65×10⁻⁷/° C., particularly preferably at least 70×10⁻⁷/° C., even more preferably at least 75×10⁻⁷/° C., most preferably at least 80×10⁻⁷/° C.

The glass plate of the present invention is preferably such that the Na₂O elution amount in water resistance test is preferably from 0.001 mg to 0.6 mg. The water resistance test is to determine the Na₂O elution amount (mg) by JIS 3502 (1995).

A glass plate such that the Na₂O elution amount in the water resistance test is at most 0.6 mg can be commonly used as a window without any problem. The Na₂O elution amount in the water resistance test is more preferably at most 0.55 mg, further preferably at most 0.5 mg, particularly preferably at most 0.4 mg, even more preferably at most 0.35 mg, most preferably at most 0.3 mg. The Na₂O elution amount in the water resistance test is preferably smaller, however, the amount of SiO₂ should be increased so as to reduce the elution amount, and if so, the viscosity at the time of melting in glass production tends to be high, and the melting property may be deteriorated. Accordingly, the Na₂O elution amount in the water resistance test is preferably at least 0.001 mg, more preferably at least 0.01 mg, further preferably at least 0.05 mg, particularly preferably at least 0.1 mg, even more preferably at least 0.15 mg, most preferably at least 0.2 mg.

Of the glass plate of the present invention, T₂ is preferably at most 1,750° C. Further, T₄ is preferably at most 1,350° C. Further, T₄-T_(L) is preferably at least −150° C. In this specification, T₂ is a temperature at which the glass viscosity becomes 10² (dPa·s), T₄ is a temperature at which the glass viscosity becomes 10⁴ (dPa·s), and T_(L) is the liquid phase temperature of the glass.

If T₂ or T₄ is higher than such a predetermined temperature, it is difficult to produce a large plate e.g. by float process, fusion process, roll out process or down draw process. T₂ is more preferably at most 1,700° C., further preferably at most 1,650° C., still more preferably at most 1,625° C., particularly preferably at most 1,600° C., even more preferably at most 1,575° C., still even more preferably at most 1,550° C., most preferably at most 1,500° C. T₄ is preferably at most 1,350° C., more preferably at most 1,300° C., further preferably at most 1,250° C., particularly preferably at most 1,200° C., even more preferably at most 1,150° C., still even more preferably at most 1,100° C., most preferably at most 1,050° C. The lower limits of T₂ and T₄ are not particularly limited, and in order to maintain the weather resistance and the glass specific gravity, typically T₂ is at least 1,200° C., and T₄ is at least 800° C. T₂ is more preferably at least 1,250° C., further preferably at least 1,300° C., particularly preferably at least 1,350° C., even more preferably at least 1,400° C. T₄ is more preferably at least 900° C., further preferably at least 940° C., particularly preferably 960° C., even more preferably at least 980° C., most preferably at least 1,000° C.

Further, in order that production by float process is possible, T₄-T_(L) is preferably at least −150° C. When T₄-T_(L) is at least −150° C., problems will not arise such that the glass is devitrified at the time of glass forming, mechanical properties of the glass will decrease, and the transparency will decrease, whereby glass having good quality can be obtained. T₄-T_(L) is more preferably at most −140° C., more preferably at most −130° C., more preferably at most −120° C., more preferably at most −110° C., more preferably at most −100° C. Further, T₄-T_(L) is more preferably at least −90° C., more preferably at least −80° C., more preferably at least −70° C., further preferably at least −60° C., further preferably at least −50° C., further preferably at least −40° C., still more preferably at least −30° C., still more preferably at least −20° C., still more preferably at least −10° C., particularly preferably at least 0° C., even more preferably at least 10° C., most preferably at least 20° C.

Of the glass plate of the present invention, T_(g) is preferably from 400° C. to 750° C. In this specification, T_(g) represents the glass transition point. When T_(g) is within such a temperature range, glass bending process can be carried out within a usual production condition range. If T_(g) is lower than 400° C., although there is no problem in forming property, problems are likely to arise such that the alkali content or the alkaline earth content tends to be too high, whereby thermal expansion of the glass may be excessive, or the weather resistance will decrease. Further, in a forming temperature region, the glass may be devitrified and may not be formed. T_(g) is more preferably at least 430° C., further preferably at least 450° C., particularly preferably at least 470° C., even more preferably at least 480° C., most preferably at least 490° C. Further, if T_(g) is too high, high temperature is required at the time of glass bending process, and production will be more difficult. T_(g) is more preferably at most 650° C., more preferably at most 600° C., more preferably at most 575° C., more preferably at most 565° C., further preferably at most 555° C., particularly preferably at most 550° C., even more preferably at most 520° C., most preferably at most 500° C.

The visible light transmittance T_(VA) is a visible light transmittance calculated by measuring the transmittance by a spectrophotometer in accordance with JIS R3106: 1998. As the weighting factors, standard illuminant A, 2 degree field of view values are employed. In this specification, the value is represented by a value as calculated as 3.85 mm plate thickness.

The value as calculated as 3.85 mm plate thickness is a value (visible light transmittance T_(VA)) of the glass plate as calculated as 3.85 mm plate thickness, considering the multiple reflection, by the reflectance of the glass plate calculated by Sellmeier's equation from the refractive index of the glass plate the transmittance of which was measured.

The visible light transmittance T_(VA) is, to secure the visibility, although it depends on the application, preferably at least 30%, more preferably at least 40%, further preferably at least 50%, particularly preferably at least 60%, even more preferably at least 65%, most preferably at least 72%. The upper limit of the visible light transmittance T_(VA) varies depending upon the application, however, if it is too high, heat rays will also be transmitted in a large amount, whereby the heat shielding property may be deteriorated. Further, it is necessary to use raw materials having less impurities so as to increase the visible light transmittance T_(VA), and such raw materials can hardly be available, and further, the glass should have a large amount of the SiO₂ component, whereby melting property will be deteriorated, and a large glass plate can hardly be produced. Accordingly, T_(VA) is preferably at most 92%. T_(VA) is more preferably at most 91.5%, further preferably at most 91%, particularly preferably at most 90.5%, even more preferably at most 90%, most preferably at most 89%.

The visible light transmittance T_(VA) is mainly adjusted by adjusting the amounts of coloring components such as Fe₂O₃ and TiO₂, however, it may be slightly adjusted also by the glass components. Further, it may be adjusted also by adjusting the glass production conditions, such as the melting temperature and the melting atmosphere.

The glass plate of the present invention, when used as a glass for vehicles, has a visible light transmittance T_(VA) of preferably higher than 70% so as to increase the visibility, and more preferably at least 71%, particularly preferably at least 72%.

The solar direct transmittance Te is as specified by ISO 13837A: 2008. In this specification, it is represented by a value as calculated as 3.85 mm plate thickness.

If the solar direct transmittance Te is too low, the visible light transmittance tends to be lowered, and visibility can hardly be secured, although it depends on the application. Further, such glass is hardly produced since a low Te is hardly achieved even by adjusting the melting temperature or the like. The solar direct transmittance Te is preferably at least 35%, more preferably at least 40%, preferably at least 45%, more preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, most preferably at least 70%. Further, although the upper limit of the solar direct transmittance Te varies depending upon the application, if the solar direct transmittance is too high, heat rays will also be transmitted in a large amount, whereby the heat shielding property may be impaired. Further, it is necessary to use raw materials having less impurities so as to increase the solar direct transmittance Te, and such raw materials can hardly be available, and further, the glass should have a large amount of the SiO₂ component, whereby melting property will be deteriorated, and

a large glass plate can hardly be produced. Accordingly, the solar direct transmittance Te is preferably at least 91%, more preferably at most 90%, further preferably at most 88%, particularly preferably at most 85%, even more preferably at most 80%, most preferably at most 75%.

The solar direct transmittance Te can be adjusted by coloring components such as Fe₂O₃ and TiO₂ or the glass components, or by adjusting the glass production conditions, such as the melting temperature and the melting atmosphere.

In a case where the glass is used as glass for vehicles having heat shielding performance, the solar direct transmittance Te is, so as to increase the heat shielding performance, preferably at most 65%, more preferably at most 60%, further preferably at most 58%, still more preferably at most 55%, particularly preferably at most 53%. On the other hand, if Te is too low, the visible light transmittance is lowered, and the visibility can hardly be secured. Accordingly, it is preferably at least 35%, more preferably at least 38%, further preferably at least 40%, particularly preferably at least 41%.

The ultraviolet transmittance Tuv is as specified by ISO 9050: 2003. In this specification, it is represented by a value as calculated as 3.85 mm plate thickness. If the ultraviolet transmittance Tuv is too high, ultraviolet rays are also transmitted in a large amount, thus adversely affecting the human body, and further, an interior material of a building, a vehicle or the like for which the glass plate of the present invention is used, may be deteriorated. Tuv is preferably at most 90%, more preferably at most 80%, further preferably at most 70%, particularly preferably at most 50%, most preferably at most 30%. It is necessary that the glass plate contains Fe₂O₃, TiO₂, CeO₂ and the like so as to lower Tuv, and if their content is high, the visible light transmittance T_(VA) may decrease, or solarization by sunlight may occur. Accordingly, Tuv is preferably at least 1%, more preferably at least 5%, particularly preferably at least 10%. Further, the ultraviolet transmittance Tuv is, so as to prevent deterioration of the interior material and to reduce the cooling load in the car, preferably at most 40%, more preferably at most 35%, further preferably at most 30%.

The glass plate of the present invention may be used also for a sensor employing infrared rays such as a laser radar. In a case where it is used as glass for a vehicle having an infrared irradiation apparatus such as a laser radar, in order to be suitably used for a laser radar, the transmittance at a wavelength of 905 nm as calculated as 3.85 mm plate thickness is preferably at least 70%, more preferably at least 75%, further preferably at least 80%, particularly preferably at least 85%, particularly preferably at least 88%, most preferably at least 90%.

The glass plate of the present invention may be used also for a sensor employing infrared rays such as a laser radar. In a case where it is used as glass for a vehicle having an infrared irradiation apparatus such as a laser radar, in order to be suitably used for a laser radar, the transmittance at a wavelength of 1,550 nm as calculated as 3.85 mm plate thickness is preferably at least 70%, more preferably at least 75%, further preferably at least 80%, particularly preferably at least 85%, particularly preferably at least 88%, most preferably at least 90%.

Of the glass plate of the present invention, the dielectric loss can be lowered by adjusting the glass composition, whereby a high radio transmittance can be achieved. Likewise, the dielectric constant can be adjusted by adjusting the composition, and a dielectric constant suitable for the application can be achieved.

Of the glass plate of the present invention, the SiO₂ content as represented by mol % based on oxides is preferably from 55% to 75%. Further, the Al₂O₃ content is preferably from 0% to 15%. Since SiO₂ and Al₂O₃ contributes to improvement of the Young's modulus, the strength required for an application to building, an application to automobiles, is likely to be secured. If the content of Al₂O₃ and/or SiO₂ is lower than the above lower limit value, the weather resistance can hardly be secured, and further, the average coefficient of linear expansion tends to be too high, and heat breakage is likely to occur. Further, if the amount of Al₂O₃ and/or SiO₂ is too large, the viscosity at the time of glass melting will increase, whereby glass production may be difficult. Further, if the amount of Al₂O₃ is too large, the radio transmittance may be low.

The SiO₂ content is more preferably at least 57%, further preferably at least 60%, still more preferably at least 63%, particularly preferably at least 64%, even more preferably at least 65%, most preferably at least 66%. The SiO₂ content is more preferably at most 74%, further preferably at most 73%, particularly preferably at most 72%, even more preferably at most 70%, most preferably at most 69%.

The Al₂O₃ content is more preferably at least 0.3%, further preferably at least 0.5%, still more preferably at least 1.0%, particularly preferably at least 1.3%, even more preferably at least 1.5%, most preferably at least 2%. The Al₂O₃ content is, in order to keep the glass viscosity T₂ to be low thereby to facilitate glass production, more preferably at most 10%, further preferably at most 6%, still more preferably at most 5%, even more preferably at most 4%, most preferably at most 3.5%.

In order to improve the radio transmittance, SiO₂+Al₂O₃, that is, the sum of the SiO₂ content and the Al₂O₃ content is preferably from 50% to 80%. Further considering keeping T₂ and T₄ to be low and facilitating glass production, SiO₂+Al₂O₃ is preferably at most 80%, more preferably at most 75%, further preferably at most 72%, even more preferably at most 71%, most preferably at most 70%. However, if SiO₂+Al₂O₃ is too low, the weather resistance may decrease and the average coefficient of linear expansion may be too high, and accordingly SiO₂+Al₂O₃ is preferably at least 55%, preferably at least 64%, more preferably at least 65%, further preferably at least 66%, even more preferably at least 67%, most preferably at least 68%.

Of the glass plate of the present invention, the B₂O₃ content is preferably from 0% 15 to 15%. By B₂O₃ being contained, the melting property and the glass strength will improve, and an effect to increase the radio transmittance will be obtained. If the amount of B₂O₃ is too large, alkali elements are likely to volatilize during melting/forming, thus leading to deterioration of the glass quality. Further, if the amount of B₂O₃ is large, the average coefficient of linear expansion becomes low, whereby physical tempering tends to be difficult. The B₂O₃ content is more preferably at most 12%, further preferably at most 10%, still more preferably at most 8%, particularly preferably at most 6%, even more preferably at most 4%, most preferably at most 2%. It is very preferred that substantially no B₂O₃ is contained.

Of the glass plate of the present invention, the MgO content is preferably from 0% to 20%. MgO is a component which promotes melting of glass raw materials and improves the weather resistance. The MgO content is more preferably at least 0.1%, further preferably at least 0.2%, particularly preferably at least 0.3%, even more preferably at least 0.5%. If the MgO content is at most 20%, devitrification is less likely to occur, and an effect to increase the radio transmittance may sometimes be obtained. The MgO content is more preferably at most 15%, further preferably at most 8%, particularly preferably at most 4%, even more preferably at most 2%, most preferably at most 1%.

In the glass plate of the present invention, CaO, SrO and/or BaO may be contained in a certain amount so as to reduce the dielectric loss of the glass. The CaO content is preferably at least 0% and at most 20%. The SrO content is preferably at least 0% and at most 15%. The BaO content is preferably from 0% to 15%. When CaO, SrO and/or BaO is contained, the melting property of the glass may improve. The CaO content is more preferably at least 3%, whereby the dielectric loss of the glass reduces, and thus the radio transmittance will improve. Further, CaO being contained in a content of at least 3% may lead to an improvement of the melting property of the glass (a decrease of T₂ and a decrease of T₄). The CaO content is further preferably at least 6%, particularly preferably at least 8%, even more preferably at least 10%, most preferably at least 11%. By the CaO content being at most 20%, the SrO content being at most 15% and the BaO content being at most 15%, an increase of the specific gravity of the glass will be avoided, and low fragility and the strength can be maintained. In order to prevent the glass from being fragile, the CaO content is more preferably at most 15%, further preferably at most 14%, particularly preferably at most 13.5%, even more preferably at most 13%, most preferably at most 12.5%. The SrO content is more preferably at most 8%, further preferably at most 3%, particularly preferably at most 2%, even more preferably at most 1%, and most preferably substantially no SrO is contained. The BaO content is more preferably at most 5%, further preferably at most 3%, particularly preferably at most 2%, even more preferably at most 1%, and most preferably substantially no BaO is contained.

In this specification, “RO” means the total content of MgO, CaO, SrO and BaO. Of the glass plate of the present invention, RO is preferably from 0% to 20%. When RO is at most 20%, an improvement of the weather resistance will be obtained. In the glass plate of the present invention, RO is more preferably at most 17%, further preferably at most 16%, particularly preferably at most 15%, even more preferably at most 14%, most preferably at most 13%.

Further, with a view to lowering T₂ and T₄ at the time of production, or with a view to increasing the Young's modulus, of the glass plate of the present invention, RO is preferably higher than 0%, more preferably at least 0.5%, further preferably at least 5%, particularly preferably at least 8%, even more preferably at least 10%, most preferably at least 12%.

Further, in order to prevent occurrence of devitrification at the time of glass melting or at the time of forming, thus leading to deterioration of the glass quality, MgO+CaO, that is, the sum of the MgO content and the CaO content is preferably from 0% to 30%. MgO+CaO is more preferably at most 25%, further preferably at most 20%, even more preferably at most 15%, most preferably at most 13%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is more preferably at least 1%, further preferably at least 2%, particularly preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

Of the glass plate of the present invention, the Na₂O content is preferably from 0% to 20%. Na₂O and K₂O are components which improve the melting property of the glass, and by either one or both being contained each in a content of at least 0.1%, T₂ and T₄ can easily be kept to be at most 1,750° C. and at most 1,350° C., respectively. Further, by Na₂O being contained, chemical tempering is possible. The Na₂O content is more preferably at least 0.1%, further preferably at least 1%, particularly preferably at least 3%, even more preferably at least 5%, most preferably at least 6%.

It is more preferred that both Na₂O and K₂O are contained, whereby the weather resistance can be improved while the melting property is maintained, and further, an effect to increase the radio transmittance may sometimes be obtained. If the Na₂O and/or K₂O content is low, the average coefficient of linear expansion cannot be made high, and heat tempering may not be conducted. Within the above predetermined amount, the glass may be utilized as a material for a window having favorable compatibility with another member.

If the Na₂O amount is too large, the average coefficient of linear expansion will be too high, whereby heat breakage is likely to occur. The Na₂O content is more preferably at most 16%, further preferably at most 14%, particularly preferably at most 12%, even more preferably at most 10%, most preferably at most 8%.

Of the glass plate of the present invention, the K₂O content is preferably at least 0% to 20%. K₂O is a component which improves the melting property of the glass and is likely to keep T₂ and T₄ to be at most 1,750° C. and at most 1,350° C., respectively, and accordingly the K₂O content is more preferably at least 0.1%, further preferably at least 0.9%, particularly preferably at least 2%, even more preferably at least 3%, most preferably at least 4%.

Further, if the amount of K₂O is too large, the average coefficient of linear expansion may be too high, and heat breakage is likely to occur. If the K₂O content is higher than 20%, the weather resistance may be lowered. The K₂O content is more preferably at most 16%, further preferably at most 14%, particularly preferably at most 12%, even more preferably at most 10%, most preferably at most 8%.

From the viewpoint of the radio transmittance, within the above range, a high radio transmittance can be obtained.

Of the glass plate of the present invention, the Li₂O content is preferably from 0% to 20%. Li₂O is a component which improves the melting property of the glass, and further, increases the Young's modulus and contributes to an improvement of the strength of the glass. By Li₂O being contained, chemical tempering is possible, and further, an effect to increase the radio transmittance may sometimes be obtained. The Li₂O content is more preferably at least 0.1%, further preferably at least 1%, particularly preferably at least 2%, even more preferably at least 3%, most preferably at least 4%.

If the amount of Li₂O is too large, devitrification or phase separation may occur at the time of glass production, whereby glass production may be difficult. The Li₂O content is more preferably at most 16%, further preferably at most 12%, particularly preferably at most 8%, even more preferably at most 7%, most preferably at most 6.5%.

In this specification, “R₂O” means the total amount of alkali metal oxides, and usually means the total content of Li₂O, Na₂O and K₂O. Of the glass plate of the present invention, R₂O is preferably from 0% to 20%. When R₂O is at most 20%, an improvement of the weather resistance will be achieved. R₂O of the glass plate of the present invention is more preferably at most 19%, further preferably at most 18.5%, particularly preferably at most 18%, even more preferably at most 17.5%, most preferably at most 17%.

Further, with a view to lowering T₂ and T₄ at the time of production, R₂O is preferably higher than 0%, more preferably at least 1%, further preferably at least 5%, still more preferably at least 6%, particularly preferably at least 8%, especially particularly preferably at least 10%, even more preferably at least 11%, most preferably at least 12%.

Na₂O/R₂O is, in order to increase the radio transmittance, preferably from 0.01 to 0.98. If Na₂O/R₂O is too low or too high, an effect to increase the radio transmittance may not sufficiently be obtained. Na₂O/R₂O is preferably at least 0.01, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.2, even more preferably at least 0.25, most preferably at least 0.3. If no Li₂O is contained, the lower content of Na₂O/R₂O is preferably somewhat high as compared with a case where Li₂O is contained, and Na₂O/R₂O is preferably at least 0.01, more preferably at least 0.1, further preferably at least 0.2, particularly preferably at least 0.3, even more preferably at least 0.35, most preferably at least 0.4.

The Na₂O/R₂O is preferably at most 0.98, more preferably at most 0.8, further preferably at most 0.6, particularly preferably at most 0.5, even more preferably at most 0.45, most preferably at most 0.4. In a case where no Li₂O is contained, the upper limit of Na₂O/R₂O is preferably somewhat high as compared with a case where Li₂O is contained, and Na₂O/R₂O is preferably at most 0.98, more preferably at most 0.9, further preferably at most 0.8, particularly preferably at most 0.7, even more preferably at most 0.65, most preferably at most 0.6.

K₂O/R₂O is, in order to increase the radio transmittance, preferably from 0.01 to 0.98. If K₂O/R₂O is too low or too high, an effect to increase the radio transmittance may not sufficiently be obtained. K₂O/R₂O is preferably at least 0.01, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.2, even more preferably at least 0.25, most preferably at least 0.3. In a case where no Li₂O is contained, the lower limit of K₂O/R₂O is preferably somewhat high as compared with a case where Li₂O is contained, and K₂O/R₂O is preferably at least 0.01, more preferably at least 0.1, further preferably at least 0.2, particularly preferably at least 0.3, even more preferably at least 0.35, most preferably at least 0.4.

K₂O/R₂O is preferably at most 0.98, more preferably at most 0.8, further preferably at most 0.6, particularly preferably at most 0.5, even more preferably at most 0.45, most preferably at most 0.4. In a case where no Li₂O is contained, the upper limit of K₂O/R₂O is preferably somewhat high as compared with a case where Li₂O is contained, and K₂O/R₂O is preferably at most 0.98, more preferably at most 0.9, further preferably at most 0.8, particularly preferably at most 0.7, even more preferably at most 0.65, most preferably at most 0.6.

R₂O×MgO is preferably low so as to increase the radio transmittance. R₂O×MgO is preferably at most 100%², more preferably at most 80%², further preferably at most 66%², still more preferably at most 60%², particularly preferably at most 50%², even more preferably at most 40%², most preferably at most 30%^(2·) In a case where no Li₂O is contained, the upper limit of R₂O×MgO is preferably somewhat high as compared with a case where Li₂O is contained, and R₂O×MgO is preferably at most 250%², more preferably at most 200%², further preferably at most 150%², particularly preferably at most 100%², even more preferably at most 85%², most preferably at most 80%^(2·).

Further, in order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃, that is, the sum of the R₂O content and the B₂O₃ content is preferably at most 30%. R₂O+B₂O₃ is more preferably at most 25%, further preferably at most 20%, even more preferably at most 19%, most preferably at most 18%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting and forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

Of the glass plate of the present invention, 7Al₂O₃+3MgO is preferably from 0% to 66%. By Al₂O₃, MgO and 7Al₂O₃+3MgO satisfying the above content ranges, an improvement of the radio transmittance of the glass material can be achieved. From the viewpoint of the radio transmittance, 7Al₂O₃+3MgO is preferably low. If 7Al₂O₃+3MgO is higher than the predetermined amount, the average coefficient of linear expansion is hardly maintained, and matching with another member may be impaired, or physical tempering may be difficult. 7Al₂O₃+3MgO is more preferably at most 60%, further preferably at most 55%, still more preferably at most 48%, particularly preferably at most 42%, even more preferably at most 30%, most preferably at most 24%.

However, from the viewpoint of the weather resistance, 7Al₂O₃+3MgO is preferably higher, and more preferably at least 0.5%, further preferably at least 5%, particularly preferably at least 10%, even more preferably at least 15%, most preferably at least 20%, whereby sufficient weather resistance will be obtained.

Of the glass plate of the present invention, 7Al₂O₃+3MgO-4Li₂O is preferably from −60% to 66%. By Al₂O₃, MgO, Li₂O and 7Al₂O₃+3MgO-4Li₂O satisfying the above content ranges, an improvement of the radio transmittance of the glass material will be achieved. With a view to increasing the radio transmittance and increasing the Young's modulus, 7Al₂O₃+3MgO-4Li₂O is preferably low. Further, if 7Al₂O₃+3MgO-4Li₂O is higher than the predetermined amount, the average coefficient of linear expansion is hardly maintained, and matching with another member may be impaired, or physical tempering may be difficult. 7Al₂O₃+3MgO-4Li₂O is more preferably at most 50%, further preferably at most 40%, particularly preferably at most 30%, even more preferably at most 20%, most preferably at most 10%.

However, from the viewpoint of the weather resistance, 7Al₂O₃+3MgO-4Li₂O is preferably high, and is more preferably at least −50%, further preferably at least −40%, particularly preferably at least −30%, even more preferably at least −20%, most preferably at least −10%, whereby sufficient weather resistance will be obtained.

Of the glass plate of the present invention, the ZrO₂ content is preferably from 0% to 5%. ZrO₂ has an effect to lower the viscosity of the glass at the time of melting and to accelerate melting, and may contributes to an improvement of heat resistance and chemical durability. If the ZrO₂ content is high, the liquid phase temperature will increase, and the average coefficient of linear expansion may increase. The ZrO₂ content is more preferably at most 2.5%, further preferably at most 2%, particularly preferably at most 1.0%, even more preferably at most 0.5%, and most preferably substantially no ZrO₂ is contained.

The glass plate of the present invention preferably satisfies 85%≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100%, whereby a glass plate can be produced from easily available glass raw materials, and the weather resistance of the glass plate is likely to be secured. The above total content is more preferably at least 88%, further preferably at least 90%, particularly preferably at least 92%, even more preferably at least 95%, still even more preferably at least 98%, most preferably at least 99.5%. Since a glass plate for a window material typically contains a coloring agent, a fining agent, etc., the upper limit of the above total content is more preferably 99.9%.

Of the glass plate of the present invention, the Fe₂O₃ content is preferably from 0.001% to 5%. Here, the Fe₂O₃ content is a total iron content including FeO which is an oxide of bivalent iron and Fe₂O₃ which is an oxide of trivalent iron. If the Fe₂O₃ content is less than 0.001%, the glass plate may not be used for an application for which heat shielding property is required, it is necessary to use an expensive raw material having a low iron content for production of the glass plate, and further, thermal radiation may reach the bottom of the melting furnace more than necessary at the time of glass melting and a burden may be imposed on the melting furnace. The Fe₂O₃ content is more preferably at least 0.005%, further preferably at least 0.01%, particularly preferably at least 0.015%, even more preferably at least 0.02%, most preferably at least 0.05%.

If the Fe₂O₃ content is higher than 5%, heat transfer by radiation may be inhibited, whereby the raw materials may not easily be melted. Further, if the Fe₂O₃ content is too high, the light transmittance in the visible region decreases (T_(V) decreases), and such a glass plate may not be suitable for an application to automobiles. Accordingly, the Fe₂O₃ content is more preferably at most 2%, further preferably at most 1%, further preferably at most 0.8%, still more preferably at most 0.6%, particularly preferably at most 0.5%, even more preferably at most 0.4%, most preferably at most 0.3%.

Of the glass plate of the present invention, in a case where an infrared irradiation apparatus such as a laser radar is used, the content of bivalent iron (FeO) as calculated as Fe₂O₃ is preferably from 0.0001% to 0.02%. In order to increase the heat absorption efficiency of the glass melt at the time of melting the glass raw materials and to improve the melting property, the content is preferably at least 0.0002%, more preferably at least 0.0006%, further preferably at least 0.0008%, particularly preferably at least 0.001%. Further, FeO absorbs light from the visible region to the near infrared region, so as to increase the transmittance in a near infrared region, the content is preferably at most 0.015%, more preferably at most 0.01%, further preferably at most 0.008%, particularly preferably at most 0.006%, particularly preferably at most 0.004%.

Of the glass plate of the present invention, in a case where it is required to have heat shielding performance, the content of bivalent iron (FeO) as calculated as Fe₂O₃ is preferably from 0.05% to 0.16%. Since FeO absorbs light from the visible region to the near infrared region and increases the heat shielding performance, the FeO content is preferably at least 0.07%, more preferably at least 0.08%, further preferably at least 0.09%, particularly preferably at least 0.1%. Further, if the FeO content is high, the glass will absorb heat at the time of production, whereby the glass production may be difficult, and accordingly the FeO content is preferably at most 0.015%, more preferably at most 0.01%, further preferably at most 0.008%, particularly preferably at most 0.006%, particularly preferably at most 0.004%.

Of the glass plate of the present invention, in a case where an infrared irradiation apparatus such as a laser radar is used, the mass ratio of bivalent iron as calculated as Fe₂O₃ to the total iron as calculated as Fe₂O₃ (hereinafter sometimes referred to as Fe-redox) is preferably higher than 0% and at most 35%. Here, the mass ratio of bivalent iron as calculated as Fe₂O₃ means the ratio of the content of FeO which is an oxide of bivalent iron as calculated as the form of Fe₂O₃, to the total iron content. That is, the content of bivalent iron as calculated as Fe₂O₃ is calculated by multiplying the FeO content by {(159.7÷2)/71.85}, since the molecular weight of FeO is 71.85 g/mol, and the molecular weight of Fe₂O₃ is 159.7 g/mol. By Fe-redox being higher than 0%, the heat absorption efficiency of the glass melt at the time of melting the glass raw materials is increased, and the melting property can be improved. As a method of adjusting Fe-redox, for example, melting at low temperature, or use of an oxidizing agent such as cerium oxide or chromium oxide may be mentioned. Fe-redox is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, particularly preferably at least 4%, most preferably at least 5%.

Further, if Fe-redox is high, the transmittance in the near infrared region may be decreased, and accordingly Fe-redox is preferably at most 35%, more preferably at most 30%, further preferably at most 25%, still more preferably at most 20%, particularly preferably at most 15%, most preferably at most 10%.

Of the glass plate of the present invention, in a case where it is required to have heat shielding performance, Fe-redox is preferably higher than 30%, more preferably at least 35%, further preferably at least 40%, still more preferably at least 45%, particularly preferably at least 50%, most preferably at least 55%. By Fe-redox being higher than 30%, the heat shielding property of the glass may be improved. As a method of increasing Fe-redox, for example, melting at high temperature, or use of a reducing agent such as tin oxide or coke may be mentioned.

In a case where the glass plate of the present invention contains SO₃, if it is melted in a reducing atmosphere so as to increase Fe-redox, sulfur (S) becomes negative bivalent sulfur. As a result, it reacts with positive bivalent iron in the glass, thus causing amber coloring, whereby the transmittance in the visible region may decrease. Accordingly, Fe-redox is preferably at most 80%, more preferably at most 75%, further preferably at most 70%, still more preferably at most 65%, particularly preferably at most 60%, most preferably at most 58%.

Of the glass plate of the present invention, the TiO₂ content is preferably from 0.001% to 5%. If the TiO₂ content is less than 0.001%, at the time of production of the glass plate of the present invention, a bubble layer may form on the molten glass surface. If a bubble layer forms, the temperature of the molten glass will not increase, whereby the molten glass can hardly be fined, whereby the productivity tends to deteriorate. In order to reduce or eliminate the bubble layer formed on the molten glass surface, a titanium compound as an anti-foaming agent may be supplied to the bubble layer formed on the molten glass surface. The titanium compound is included into the molten glass, and is present as TiO₂. This titanium compound may be an inorganic titanium compound (such as titanium tetrachloride or titanium oxide) or may be an organic titanium compound. The organic titanium compound may be a titanate or its derivative, a titanium chelate or its derivative, a titanium acylate or its derivative, or titanium oxalate. The TiO₂ content is more preferably at least 0.005%, further preferably at least 0.01%, particularly preferably at least 0.02%, even more preferably at least 0.05%, most preferably at least 0.06%. Further, since TiO₂ has absorption in the ultraviolet region, it is preferably added for an application in which ultraviolet rays should be blocked. In such a case, the TiO₂ content is preferably at least 0.04%, more preferably at least 0.1%, further preferably at least 0.2%, particularly preferably at least 0.5%. However, if the TiO₂ content is high, the liquid phase temperature will increase, and devitrification may occur, and further, since TiO₂ has absorption in the visible region, yellow coloring may occur, and accordingly the TiO₂ content is preferably at most 5%. The TiO₂ content is more preferably at most 1%, further preferably at most 0.5%, particularly preferably at most 0.3%, even more preferably at most 0.2%, most preferably at most 0.1%.

In a case where an infrared irradiation apparatus such as a laser radar is used, if moisture is present in the glass, which has absorption in the near infrared region, the transmittance in the near infrared region decreases, and such glass is not suitable for application to an infrared irradiation apparatus. Moisture in the glass is generally represented by a value p-OH, and p-OH is preferably at most 0.5, more preferably at most 0.4, further preferably at most 0.3, particularly preferably at most 0.2. p-OH may be obtained in accordance with the following formula from the transmittance of the glass plate measured by using FT-IR (Fourier transform infrared spectrophotometer):

β-OH (mm⁻¹)=(1/X)log₁₀(T_(A)/T_(B))

X: thickness (mm) of glass plate

T_(A): transmittance (%) at a reference wave number of 4,000 cm⁻¹

T_(B): minimum transmittance (%) in the vicinity of hydroxy group absorption wave number of 3,600 cm⁻¹

The heat shielding property of the glass plate of the present invention can be increased when moisture is present in the glass, which has absorption in the near infrared region. So as to increase the heat shielding property, p-OH in the glass is preferably at least 0.05, more preferably at least 0.07, further preferably at least 0.1, particularly preferably at least 0.15.

The glass plate of the present invention further preferably has composition ranges as identified in the following ten embodiments, whereby more excellent properties will be achieved.

The glass plate according to embodiment 1 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

0≤Al₂O₃≤9

0≤B₂O₃≤15

0≤MgO≤15

0≤CaO≤20

0≤SrO≤15

0≤BaO≤15

0≤Li₂O<0.01

1.2≤Na₂O≤15.6

3.5≤K₂O≤12.5

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

4.7≤R₂O≤19.5

0≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

42<7Al₂O₃+3MgO≤66

0.25≤Na₂O/R₂O≤0.8

R₂O+B₂O₃≤23

0≤PbO<0.001.

Within the range of the embodiment 1, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 1, the following range is more preferred. The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 57%, further preferably at least 60%. In order to suppress deterioration of the viscosity by a viscosity increase, it is more preferably at most 70%, further preferably at most 68%, particularly preferably at most 66%.

The Al₂O₃ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 2%, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%. In order to increase the radio transmittance, it is more preferably at most 8%, further preferably at most 7%, still more preferably at most 6%, particularly preferably at most 5%, most preferably at most 4.5%. The MgO content is, with a view to improving the melting property and the weather resistance, more preferably at least 0.1%, further preferably at least 0.25%, particularly preferably at least 0.4%. With a view to improving the viscosity, it is more preferably at most 13%, further preferably at most 10%, still more preferably at most 7%, particularly preferably at most 5%, particularly preferably at most 4.5%, especially particularly preferably at most 4%, even more preferably at most 3%, still even more preferably at most 2%, most preferably at most 1%.

The CaO content is, in order to improve the melting property and to increase the radio transmittance, preferably at least 1%. It is more preferably at least 2%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 8%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 16%, particularly preferably at most 15%, even more preferably at most 14%, particularly preferably at most 13%, most preferably at most 12%.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and if SrO is contained, its content is preferably at least 0.5%, more preferably at least 1%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 5%, still even more preferably at most 3%, most preferably at most 2%.

BaO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where BaO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The BaO content is, so as to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 9%, even more preferably at most 7%, still even more preferably at most 5%, most preferably at most 3%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 7%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 15%, further preferably at most 14%, particularly preferably at most 13%, even more preferably at most 12%, still even more preferably at most 11%, most preferably at most 10%.

The K₂O content is, in order to increase the radio transmittance and to adjust the average coefficient of linear expansion, more preferably at least 4%, further preferably at least 4.5%, particularly preferably at least 5%, even more preferably at least 5.5%, most preferably at least 6%. Further, K₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 12%, further preferably at most 11.5%, particularly preferably at most 11%, even more preferably at most 10.5%, most preferably at most 10%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, the content is more preferably at most 1.8%, further preferably at most 1.5%.

The R₂O content is, with a view to improving the melting property, more preferably at least 5%, more preferably at least 6%, further preferably at least 7%, still more preferably at least 8%, particularly preferably at least 10%. On the other hand, in order to improve the weather resistance, it is more preferably at most 18.5%, further preferably at most 17%, still more preferably at most 16%, particularly preferably at most 15%, most preferably at most 14%.

The RO content is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 7%, particularly preferably at least 10%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, it is more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 15%.

The glass plate according to the present embodiment more preferably satisfies 85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100, whereby the glass plate can be produced from easily available glass raw materials.

7Al₂O₃+3MgO is, in order to increase the radio transmittance, more preferably at least 43%, further preferably at least 44%, particularly preferably at least 44.5%, even more preferably at least 45%, most preferably at least 45.5%. Further, 7Al₂O₃+3MgO is more preferably at most 60%, further preferably at most 58%, particularly preferably at most 56%, even more preferably at most 52%, most preferably at most 50%.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.3, further preferably at least 0.35, particularly preferably at least 0.4, even more preferably at least 0.43, most preferably at least 0.45. Further, Na₂O/R₂O is more preferably at most 0.75, further preferably at most 0.7, particularly preferably at most 0.65, still even more preferably at most 0.6, most preferably at most 0.55.

In the embodiment 1 of the present invention, SiO₂+Al₂O₃ is preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, still even more preferably at least 67%, most preferably at least 68%. Further, SiO₂+Al₂O₃ is preferably at most 80%, more preferably at most 78%, particularly preferably at most 76%, even more preferably at most 74%, most preferably at most 72%.

R₂O×MgO is, in order to increase the radio transmittance, preferably lower. In a case where no Li₂O is contained, the upper limit of R₂O×MgO is preferably higher, and is preferably at most 250%².

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 23%. R₂O+B₂O₃ is more preferably at most 22%, more preferably at most 21%, further preferably at most 20%, still even more preferably at most 19%, most preferably at most 18.5%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 4%, further preferably at least 8%, even more preferably at least 10%, most preferably at least 12%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is preferably at most 15%, more preferably at most 12%, more preferably at most 10%, more preferably at most 7%, further preferably at most 5%, still more preferably at most 4%, even more preferably at most 3%, still even more preferably at most 2%, most preferably at most 1%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is more preferably at most 20%, further preferably at most 18%, particularly preferably at most 16%, even more preferably at most 15%, still even more preferably at most 14%, most preferably at most 13%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 5%, still even more preferably at least 7%, most preferably at least 9%, still most preferably at least 10%.

By the glass plate satisfying such conditions, a high radio transmittance in a high frequency band can be achieved.

The glass plate according to embodiment 2 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

0≤Al₂O₃≤6

0≤B₂O₃≤15

0≤MgO≤14

0≤CaO≤20

0≤SrO≤15

0≤BaO≤15

0Li₂O≤0.01

4≤Na₂O≤17

1.9≤K₂O≤14.2

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤3

5.9≤R₂O≤20

0≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

23.5<7Al₂O₃+3MgO≤42

0.22≤Na₂O/R₂O≤0.85

R₂O×MgO≤66

55≤SiO₂+Al₂O₃≤76

0PbO<0.001.

Within the range of the embodiment 2, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 2, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 65%, still more preferably at least 66%, particularly preferably at least 67%, most preferably at least 68%, and with a view to improving the viscosity, more preferably at most 74%, further preferably at most 73%, particularly preferably at most 72%, most preferably at most 71%.

The Al₂O₃ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 1.5%, most preferably at least 2%, and in order to increase the radio transmittance, more preferably at most 5%, further preferably at most 4%, still more preferably at most 3%.

The MgO content is, with a view to improving the melting property and the weather resistance, more preferably at least 0.1%, further preferably at least 0.25%, particularly preferably at least 0.35%, and with a view to improving the viscosity, more preferably at most 13%, further preferably at most 10%, further preferably at most 9%, still more preferably at most 7%, particularly preferably at most 5%, especially particularly preferably at most 4%, even more preferably at most 3%, still even more preferably at most 2%, most preferably at most 1%.

The CaO content is, in order to improve the melting property and to increase the radio transmittance, preferably at least 1%, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 6%, even more preferably at least 8%, most preferably at least 10%. The CaO content is, with a view to suppressing devitrification, preferably at most 18%, further preferably at most 17%, particularly preferably at most 16%, even more preferably at most 15%, most preferably at most 14%.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5%, more preferably at least 1%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 7%, even more preferably at most 4%, most preferably at most 2%.

BaO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where BaO is contained, its content is preferably at least 0.5%. It is more preferably at least 1%, particularly preferably at least 2%. The BaO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 5%, most preferably at most 3%.

In order to increase the radio transmittance while keeping the melting property, the Na₂O content is preferably from 4% to 17%. Within such a range, the above-described range of Na₂O/R₂O and range of R₂O×MgO are likely to be maintained in proper ranges, and the weather resistance is secured. The Na₂O content is more preferably at least 4.5%, further preferably at least 5%, most preferably at least 6%. Further, the Na₂O content is more preferably at most 16%, further preferably at most 14%, particularly preferably at most 12%, even more preferably at most 11%, most preferably at most 10%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 2%, further preferably at least 3.5%, still more preferably at least 4%, particularly preferably at least 5%, even more preferably at least 5.5%, most preferably at least 6%, and more preferably at most 13.5%, further preferably at most 12%, particularly preferably at most 11%, even more preferably at most 10.5%, most preferably at most 10%.

ZrO₂ may be contained so as to improve chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, the ZrO₂ content is more preferably at most 1.8%, further preferably at most 1.5%.

The R₂O content is, with a view to improving the melting property, more preferably at least 7%, further preferably at least 8%, particularly preferably at least 10%. On the other hand, in order to improve the weather resistance, it is more preferably at most 18%, further preferably at most 16%, still more preferably at most 14%, particularly preferably at most 13%, most preferably at most 12%.

The RO content is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 2%, more preferably at least 5%, further preferably at least 7%, still more preferably at least 8%, particularly preferably at least 10%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, it is more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 15%.

The glass plate according to the embodiment 2 more preferably satisfies 85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100, whereby the glass plate can be produced from easily available glass raw materials.

7Al₂O₃+3MgO is, in order to increase the radio transmittance, more preferably at least 24%, further preferably at least 25%, particularly preferably at least 26%, even more preferably at least 28%, most preferably at least 30%. Further, 7Al₂O₃+3MgO is more preferably at most 40%, further preferably at most 38%, particularly preferably at most 37%, even more preferably at most 36%, most preferably at most 35%.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.3, further preferably at least 0.35, particularly preferably at least 0.4, most preferably at least 0.45. Further, Na₂O/R₂O is more preferably at most 0.8, further preferably at most 0.75, particularly preferably at most 0.7, even more preferably at most 0.6, most preferably at most 0.55.

SiO₂+Al₂O₃ is, in order to improve the melting property and to improve the radio transmittance, more preferably at least 60%, further preferably at least 65%, particularly preferably at least 67%, most preferably at least 68%. Further, SiO₂+Al₂O₃ is preferably at most 76%, more preferably at most 75%, further preferably at most 74%, particularly preferably at most 73%, most preferably at most 72%.

R₂O×MgO is, in order to increase the radio transmittance, preferably lower. R₂O×MgO is preferably at most 66%², more preferably at most 60%², further preferably at most 50%², particularly preferably at most 40%², even more preferably at most 30%², most preferably at most 25%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 30%, more preferably at most 28%, further preferably at most 25%, even more preferably at most 20%, still even more preferably at most 18%, most preferably at most 16%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, still even more preferably at least 6%, most preferably at least 8%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, by a high Na₂O content, the B₂O₃ content is preferably at most 15%. The B₂O₃ content is more preferably at most 12%, further preferably at most 10%, even more preferably at most 8%, still even more preferably at most 6%, most preferably at most 5%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is more preferably at most 18%, further preferably at most 16%, even more preferably at most 14%, most preferably at most 12%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

The glass plate according to the embodiment 2 tends to be devitrified, and accordingly the TiO₂ content is preferably at most 3%, more preferably at most 2%, further preferably at most 1%, particularly preferably at most 0.5%, even more preferably at most 0.2%, most preferably at most 0.1%.

The glass plate according to embodiment 3 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

1.3≤Al₂O₃≤3.35

0≤B₂O₃≤15

0≤MgO≤4.8

0≤CaO≤20

0≤SrO≤4

0≤BaO≤15

0≤Li₂O<0.01

0.1≤Na₂O≤16

1≤K₂O≤16

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤1.5

1.1≤R₂O≤20

0≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

0≤7Al₂O₃+3MgO≤23.5

0.05≤Na₂O/R₂O≤0.8

0≤R₂O+B₂O₃≤22

0≤PbO<0.001

0≤ZnO≤8.

Within the range of the embodiment 3, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 3, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 65%, particularly preferably at least 68%. With a view to improving the viscosity, the SiO₂ content is more preferably at most 74%, further preferably at most 73.5%, particularly preferably at most 73%, most preferably at most 72.5%.

The Al₂O₃ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 1.5%, further preferably at least 1.7%, particularly preferably at least 1.9%, most preferably at least 2%. In order to increase the radio transmittance, it is more preferably at most 3.0%, further preferably at most 2.5%.

The MgO content is, with a view to improving the melting property and the weather resistance, more preferably at least 0.1%, further preferably at least 0.25%, particularly preferably at least 0.5%. With a view to improving the viscosity, the MgO content is more preferably at most 4%, further preferably at most 3%, particularly preferably at most 2%, most preferably at most 1%.

The CaO content is, in order to improve the melting property and to increase the radio transmittance, preferably at least 1%, more preferably at least 2%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 8%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 16%, particularly preferably at most 15%, even more preferably at most 14%, most preferably at most 13%.

BaO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where BaO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The BaO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, still more preferably at most 9%, particularly preferably at most 8%, especially particularly preferably at most 4%, most preferably at most 3%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 2%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 7%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 15%, further preferably at most 14%, particularly preferably at most 13%, even more preferably at most 12%, most preferably at most 11%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 1.5%, further preferably at least 2%, particularly preferably at least 2.5%, most preferably at least 3%, and more preferably at most 13%, further preferably at most 11%, particularly preferably at most 10%, even more preferably at most 9%, most preferably at most 8%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, the ZrO₂ content is more preferably at most 1.8%, further preferably at most 1.5%.

The R₂O content is, with a view to improving the melting property, more preferably at least 5%, further preferably at least 6%, particularly preferably at least 8%, most preferably at least 10%. On the other hand, in order to improve the weather resistance, it is more preferably at most 19%, further preferably at most 17%, still more preferably at most 15%, particularly preferably at most 14.5%, most preferably at most 14%.

RO is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 6%, particularly preferably at least 9%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, more preferably at most 18%, further preferably at most 16%, still more preferably at most 15%, particularly preferably at most 13%, most preferably at most 12%.

7Al₂O₃+3MgO is, in order to increase the radio transmittance, more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 5%, even more preferably at least 8%, most preferably at least 10%. Further, 7Al₂O₃+3MgO is more preferably at most 23%, further preferably at most 22.5%, still more preferably at most 22%.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.1, further preferably at least 0.15, particularly preferably at least 0.2, even more preferably at least 0.25, most preferably at least 0.3. Further, Na₂O/R₂O ratio is more preferably at most 0.75, further preferably at most 0.7, particularly preferably at most 0.65, especially particularly preferably at most 0.6, most preferably at most 0.55.

SiO₂+Al₂O₃ is more preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, still even more preferably at least 68%, most preferably at least 71%. Further, SiO₂+Al₂O₃ is more preferably at most 80%, further preferably at most 78%, particularly preferably at most 76%, even more preferably at most 75%, most preferably at most 74%.

R₂O×MgO is, in order to increase the radio transmittance, more preferably low. R₂O×MgO is preferably at most 80%², more preferably at most 60%², further preferably at most 40%², particularly preferably at most 30%², even more preferably at most 20%², most preferably at most 10%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 22%, more preferably at most 20%, further preferably at most 18.5%, even more preferably at most 18%, most preferably at most 16%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

In the embodiment 3 also, in order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, by a relative increase of the Na₂O component in the glass to the total alkali amount, the B₂O₃ content is preferably at most 15%, more preferably at most 10%, further preferably at most 8%, even more preferably at most 6%, most preferably at most 5%.

The glass plate according to the embodiment 3 more preferably satisfies 85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100, whereby the glass plate can be produced from easily available glass raw materials. Further, in the case of a composition with small Al₂O₃ and MgO as the glass of the present embodiment, in order to secure also the weather resistance of the glass plate, the above total amount is more preferably at least 98%. It is more preferably at least 98.5%, particularly preferably at least 99%. Since a glass plate for a window material typically contains a coloring agent, a fining agent, etc., the upper limit of the total amount is even more preferably 99.9%.

Further, in the embodiment 3, in order to prevent the glass from being fragile and having lowered strength, since the amounts of Al₂O₃ and MgO are small, or for weight saving of the glass plate, the SrO content is preferably at most 4%, more preferably at most 2.5%, further preferably at most 2%, and particularly preferably substantially no SrO is contained.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is preferably at most 18%, more preferably at most 16%, further preferably at most 14%, even more preferably at most 13%, most preferably at most 12%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

The glass plate according to the embodiment 3 particularly tends to be devitrified. Accordingly, the TiO₂ content is preferably at most 1.5%, more preferably at most 1%, further preferably at most 0.5%, particularly preferably at most 0.2%, even more preferably at most 0.1%, most preferably at most 0.05%.

The glass plate according to the embodiment 3 may contain ZnO, which has an effect to suppress devitrification. If it is contained in a large amount, defects may occur at the time of production in a float bath, and accordingly the ZnO content is preferably at most 8%, more preferably at most 6%, more preferably at most 4%, further preferably at most 3%, further preferably at most 2%, still more preferably at most 1%, still more preferably at most 0.5%.

The glass plate according to embodiment 4 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

1.44≤Al₂O₃≤9

0≤B₂O₃≤2

0≤MgO≤15

0≤CaO≤20

0≤SrO≤15

0≤BaO≤1

0.01≤Li₂O≤19.1

0≤Na₂O≤16

0.9≤K₂O≤16

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

0.91≤R₂O≤20

0≤RO≤20

98≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

10<7Al₂O₃+3MgO−4Li₂O≤66

0≤Na₂O/R₂O≤0.8

0≤PbO<0.001.

Within the range of the embodiment 4, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the ratio transmittance, in the embodiment 4, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 64%, particularly preferably at least 65%, and with a view to improving the viscosity, more preferably at most 72%, further preferably at most 70%, particularly preferably at most 68%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 2%, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, and in order to improve the weather resistance, more preferably at most 15%, further preferably at most 14%, particularly preferably at most 13%, even more preferably at most 12%, still even more preferably at most 10%, most preferably at most 9%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 1%, further preferably at least 1.5%, particularly preferably at least 2%, even more preferably at least 2.5%, most preferably at least 3%, and more preferably at most 15%, further preferably at most 13%, particularly preferably at most 12%, even more preferably at most 10%, most preferably at most 9%.

The Li₂O content is, in order to increase the melting property and the Young's modulus and to improve the radio transmittance, more preferably at least 1%, further preferably at least 2%, particularly preferably at least 3%, even more preferably at least 4%, and further, Li₂O may cause devitrification or phase separation, its content is more preferably at most 15%, further preferably at most 12%, particularly preferably at most 10%, even more preferably at most 8%, most preferably at most 7%.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 6%, most preferably at most 4%.

7Al₂O₃+3MgO-4Li₂O is, in order to increase the radio transmittance, more preferably at least 12, further preferably at least 14, particularly preferably at least 16, even more preferably at least 18, most preferably at least 20. Further, 7Al₂O₃+3MgO-4Li₂O is more preferably at most 60, further preferably at most 55, particularly preferably at most 50, even more preferably at most 45, most preferably at most 40.

Na₂O/R₂O is, to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, most preferably at least 0.25. Further, Na₂O/R₂O is more preferably at most 0.8, further preferably at most 0.75, particularly preferably at most 0.7, even more preferably at most 0.6, most preferably at most 0.5.

In the embodiment 4, in order to lower the glass viscosity at the time of melting/forming for easy production, SiO₂+Al₂O₃ is preferably at least 50%, further preferably at least 60%, particularly preferably at least 65%, even more preferably at least 66%, most preferably at least 68%. Further, SiO₂+Al₂O₃ is preferably at most 75%, further preferably at most 74%, particularly preferably at most 73%, even more preferably at most 72%, most preferably at most 71%.

In order to lower the glass viscosity at the time of melting/forming for easy production and to increase the radio transmittance, the Al₂O₃ content is preferably at most 9%, more preferably at most 8%, further preferably at most 7%, particularly preferably at most 6%, even more preferably at most 5%, most preferably at most 4%, and in order to secure the weather resistance, it is more preferably at least 1.5%, further preferably at least 2%, particularly preferably at least 2.5%.

K₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, most preferably at least 0.25. Further, K₂O/R₂O is more preferably at most 0.95, further preferably at most 0.9, particularly preferably at most 0.7, even more preferably at most 0.5, most preferably at most 0.4.

In the embodiment 4, in order to increase the radio transmittance, R₂O×MgO is preferably lower. R₂O×MgO is preferably at most 200%², more preferably at most 180%², further preferably at most 160%², particularly preferably at most 140%², even more preferably at most 120, still even more preferably at most 100%², most preferably at most 80%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 19%, more preferably at most 18.5%, further preferably at most 18%, even more preferably at most 17%, most preferably at most 16%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is preferably at most 2%, more preferably at most 1.8%, further preferably at most 1.5%, even more preferably at most 1.0%, most preferably at most 0.5%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is preferably at most 20%, more preferably at most 18%, further preferably at most 16%, even more preferably at most 15%, most preferably at most 14%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

Further, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, the BaO content is preferably at most 1%, more preferably at most 0.5%, further preferably at most 0.1%, and particularly preferably substantially no BaO is contained.

In the same manner as above, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, SrO+BaO+ZrO₂ is preferably at most 8%, more preferably at most 7%, further preferably at most 6%, particularly preferably at most 5%, even more preferably at most 3%, most preferably at most 2%.

Further, in order to increase the radio transmittance, the MgO content is more preferably at most 14%, further preferably at most 12%, particularly preferably at most 10%, even more preferably at most 8%, still even more preferably at most 6%, most preferably at most 4.5%.

In order to improve the melting property and to increase the radio transmittance, the CaO content is preferably at least 0.5%, more preferably at least 1%, further preferably at least 3%, particularly preferably at least 5%, even more preferably at least 7%, most preferably at least 8%, and with a view to suppressing devitrification, it is more preferably at most 18%, further preferably at most 16%, particularly preferably at most 14%, even more preferably at most 13%, most preferably at most 12%.

ZrO₂ may be contained so as to improve chemical durability, and in a case where ZrO₂ is contained, its content is preferably at least 0.5%. Further, in order that the average coefficient of linear expansion is not high, it is more preferably at most 1.8%, further preferably at most 1.5%.

R₂O is, with a view to improving melting property, more preferably at least 5%, more preferably at least 6%, further preferably at least 7%, particularly preferably at least 8%. On the other hand, in order to improve the weather resistance, it is more preferably at most 18%, further preferably at most 17%, still more preferably at most 16%, particularly preferably at most 15%, most preferably at most 14%.

RO is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 6%, particularly preferably at least 8%, and on the other hand, with a view to improving the weather resistance and suppressing devitrification, it is more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 15%.

The glass plate according to embodiment 5 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents.

55≤SiO₂≤75

0≤Al₂O₃≤7.8

0≤B₂O₃≤2

0≤MgO≤11.8

2≤CaO≤20

0≤SrO≤15

0≤BaO≤1

2.5≤Li₂O≤19.52

0.15≤Na₂O≤17.17

0.33≤K₂O≤16.5

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

2.98≤R₂O≤20

2≤RO≤20

98≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

−10 ≤7Al₂O₃+3MgO−4Li₂O≤10

0.05≤Na₂O/R₂O≤0.85

0.11≤K₂O/R₂O≤0.83

0≤PbO<0.001

Within the range of the embodiment 5, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 5, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 63%, particularly preferably at least 65%, and with a view to improving the viscosity, more preferably at most 73%, more preferably at most 71%, further preferably at most 70%, particularly preferably at most 69%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 0.5%, more preferably at least 1%, further preferably at least 2%, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%, and in order to improve the weather resistance, it is more preferably at most 15%, further preferably at most 13%, particularly preferably at most 11%, even more preferably at most 10%, most preferably at most 8%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 0.5%, more preferably at least 2%, further preferably at least 3%, particularly preferably at least 4%, even more preferably at least 5%, most preferably at least 6%, and with a view to improving the viscosity, it is more preferably at most 16%, further preferably at most 14%, particularly preferably at most 12%, even more preferably at most 11%, most preferably at most 10%.

The Li₂O content is, in order to increase the melting property and the Young's modulus, and to improve the radio transmittance, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%. Further, Li₂O may cause devitrification and phase separation, its content is more preferably at most 15%, further preferably at most 12%, particularly preferably at most 10%, even more preferably at most 8%, most preferably at most 7%.

7Al₂O₃+3MgO-4Li₂O is, in order to increase the radio transmittance, more preferably at least −9, further preferably at least −6, particularly preferably at least −4, even more preferably at least −2, most preferably at least −1. Further, 7Al₂O₃+3MgO-4Li₂O is more preferably at most 9.5, further preferably at most 9, particularly preferably at most 8.5, even more preferably at most 8.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5, more preferably at least 1%, particularly preferably at least 2%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 6%, most preferably at most 4%.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.1, further preferably at least 0.15, particularly preferably at least 0.2, even more preferably at least 0.25, most preferably at least 0.3. Further, Na₂O/R₂O is more preferably at most 0.9, further preferably at most 0.8, particularly preferably at most 0.7, even more preferably at most 0.6, most preferably at most 0.5.

In the embodiment 5, SiO₂+Al₂O₃ is more preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, still even more preferably at least 67%, most preferably at least 68. Further, SiO₂+Al₂O₃ is more preferably at most 80%, further preferably at most 78%, particularly preferably at most 76%, even more preferably at most 75%, even more preferably at most 74%, still even more preferably at most 73%, most preferably at most 72.5%.

In order to lower the glass viscosity at the time of melting/forming for easy production and to increase the radio transmittance, the Al₂O₃ content is more preferably at most 7%, further preferably at most 6%, particularly preferably at most 5%, even more preferably at most 4.5%, still even more preferably at most 3%, most preferably at most 3.5%. The lower limit of Al₂O₃ is not particularly limited, and in order to secure the weather resistance, the Al₂O₃ content is more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 1.5%, especially particularly preferably at least 1.8%, even more preferably at least 2%, most preferably at least 2.5%.

K₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.15, further preferably at least 0.2, particularly preferably at least 0.25, even more preferably at least 0.28, most preferably at least 0.3. Further, K₂O/R₂O is more preferably at most 0.80, further preferably at most 0.7, particularly preferably at most 0.6, even more preferably at most 0.5, most preferably at most 0.4. When Na₂O/R₂O and K₂O/R₂O are within the predetermined ranges, the radio transmittance is likely to be high.

In the embodiment 5, R₂O×MgO is preferably lower, so as to increase the radio transmittance. R₂O×MgO is preferably at most 200%², more preferably at most 150%², more preferably at most 130%², more preferably at most 120%², further preferably at most 100%², still more preferably at most 80%², particularly preferably at most 60%² even more preferably at most 40%², most preferably at most 30%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 19%. R₂O+B₂O₃ is more preferably at most 18.5%, further preferably at most 18%, even more preferably at most 17%, most preferably at most 16%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is preferably at most 2%. The B₂O₃ content is more preferably at most 1.5%, further preferably at most 1%, most preferably at most 0.5%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is preferably at most 17%, more preferably at most 15%, further preferably at most 14%, even more preferably at most 13%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

Further, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, the BaO content is preferably at most 1%, more preferably at most 0.8%, more preferably at most 0.5%, further preferably at most 0.1%, particularly preferably substantially no BaO is contained.

In the same manner as above, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, SrO+BaO+ZrO₂ is more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 4%, most preferably at most 2%.

Further, in order to increase the radio transmittance, the MgO content is preferably at most 11.8%, more preferably at most 10%, further preferably at most 7%, particularly preferably at most 6%, even more preferably at most 5%, still even more preferably at most 4%, still even more preferably at most 3%, most preferably at most 2%. With a view to improving the melting property, it is preferably at least 0%, more preferably at least 0.1%, still more preferably at least 0.3%, particularly preferably at least 0.5%.

In order to improve the melting property and to increase the radio transmittance, the CaO content is preferably at least 2%, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 8%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 17%, particularly preferably at most 16%, even more preferably at most 14%, most preferably at most 12%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5, and in order that the average coefficient of linear expansion is not high, it is more preferably at most 1.8%, further preferably at most 1.5%.

R₂O is, with a view to improving the melting property, more preferably at least 5%, more preferably at least 6%, more preferably at least 7%, further preferably at least 9%, particularly preferably at least 10%, and on the other hand, in order to improve the weather resistance, it is more preferably at most 18%, further preferably at most 16.5%, still more preferably at most 15.5%, particularly preferably at most 14.5%, most preferably at most 13.5%.

RO is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 7%, particularly preferably at least 8%, most preferably at least 10%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, it is more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 14%.

The glass plate according to embodiment 6 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

0Al₂O₃≤5.5

0≤B₂O₃≤2

0≤MgO≤10.5

0≤CaO≤20

0≤SrO≤15

0≤BaO≤15

2.5≤Li₂O≤20

0≤Na₂O≤18.5

0≤K₂O≤18.5

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

2.5≤R₂O≤20

0≤RO≤20

98≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO≤100

−60 ≤7Al₂O₃+3MgO−4Li₂O≤−10

0≤PbO<0.001.

Within the range of the embodiment 6, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 6, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 63%, particularly preferably at least 65%, and with a view to improving the viscosity, it is more preferably at most 72%, further preferably at most 71%, particularly preferably at most 70%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 1%, further preferably at least 2%, particularly preferably at least 3%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 15%, further preferably at most 12%, particularly preferably at most 10%, even more preferably at most 8%, most preferably at most 7%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 0.5%, more preferably at least 1%, further preferably at least 2%, still more preferably at least 3%, particularly preferably at least 4%, and with a view to improving the viscosity, it is more preferably at most 15.5%, further preferably at most 14%, particularly preferably at most 12%, even more preferably at most 10%, still even more preferably at most 8%, most preferably at most 7%.

The Li₂O content is, in order to increase the melting property and the Young's modulus, and to improve the radio transmittance, more preferably at least 3%, further preferably at least 4%. Further, Li₂O may cause devitrification and phase separation, its content is more preferably at most 15%, more preferably at most 14%, more preferably at most 13%, further preferably at most 12%, particularly preferably at most 10%, even more preferably at most 8%, most preferably at most 7%.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5%. It is more preferably at least 1%, particularly preferably at least 2%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 6%, most preferably at most 4%.

7Al₂O₃+3MgO-4Li₂O is, in order to improve the water resistance of the glass, more preferably at least −50, further preferably at least −40, particularly preferably at least −35, even more preferably at least −30, most preferably at least −25. Further, in order to increase the radio transmittance of the glass, 7Al₂O₃+3MgO-4Li₂O is more preferably at most −10.5, more preferably at most −11, further preferably at most −12, particularly preferably at most −13, even more preferably at most −14, most preferably at most −15.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, most preferably at least 0.25. Further, Na₂O/R₂O is, with a view to improving the weather resistance, more preferably at most 0.95, further preferably at most 0.9, particularly preferably at most 0.8, even more preferably at most 0.6, still even more preferably at most 0.5, most preferably at most 0.4.

In the embodiment 6, in order to lower the viscosity at the time of glass melting/forming for easy production, SiO₂+Al₂O₃ is preferably at least 50%, more preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, most preferably at least 68%. Further, SiO₂+Al₂O₃ is preferably at most 80%, further preferably at most 78%, particularly preferably at most 76%, even more preferably at most 74%, most preferably at most 72.5%.

In order to lower the glass viscosity at the time of melting/forming for easy production, the Al₂O₃ content is more preferably at most 5%, further preferably at most 4.5%, particularly preferably at most 4%, even more preferably at most 3.5%, most preferably at most 3%. The lower limit of the Al₂O₃ content is not particularly limited, and in order to secure the weather resistance, Al₂O₃ content is more preferably at least 0.1%, more preferably at least 0.2%, more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 1.5%, even more preferably at least 2%.

K₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, most preferably at least 0.25. Further, K₂O/R₂O is, with a view to improving the weather resistance, more preferably at most 0.95, further preferably at most 0.9, particularly preferably at most 0.7, even more preferably at most 0.5, most preferably at most 0.4. By Na₂O/R₂O and K₂O/R₂O being within the predetermined ranges, the radio transmittance is likely to be increased.

In the embodiment 6, R₂O×MgO is more preferably lower, so as to increase the radio transmittance. R₂O×MgO is more preferably at most 200%², more preferably at most 160%², more preferably at most 120%², further preferably at most 100%², still more preferably at most 80%², particularly preferably at most 60%², even more preferably at most 40%², most preferably at most 20%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 19%, more preferably at most 18.5%, further preferably at most 18%, even more preferably at most 17%, most preferably at most 16%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 2.5%, more preferably at least 5%, further preferably at least 10%, even more preferably at least 12%, most preferably at least 13%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is preferably at most 2%. The B₂O₃ content is more preferably at most 1.5%, further preferably at most 1%, even more preferably at most 0.75%, most preferably at most 0.5%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is preferably at most 15%, more preferably at most 14%, further preferably at most 13%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, and glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

Further, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, the BaO content is preferably at most 15%, more preferably at most 8%, further preferably at most 4%, particularly preferably at most 2%, even more preferably at most 1%, still more preferably at most 0.5%, most preferably substantially no BaO is contained.

In the same manner as above, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, SrO+BaO+ZrO₂ is preferably at most 15%. It is more preferably at most 14%, further preferably at most 10%, still more preferably at most 8%, particularly preferably at most 5%, even more preferably at most 4%, most preferably at most 2%.

Further, in order to increase the radio transmittance, the MgO content is more preferably at most 10.5%, further preferably at most 8%, particularly preferably at most 6%, even more preferably at most 4%, most preferably at most 2%. With a view to improving the melting property, it is preferably at least 0%, more preferably at least 0.1%, still more preferably at least 0.2%, particularly preferably at least 0.3%, most preferably at least 0.5%.

In order to improve the melting property and to increase the radio transmittance, the CaO content is more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 2%, even more preferably at least 3%, still even more preferably at least 6%, most preferably at least 8%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 17%, particularly preferably at most 16%, even more preferably at most 15%, most preferably at most 14%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, it is more preferably at most 1.8%, further preferably at most 1.5%.

R₂O is, with a view to improving the melting property, more preferably at least 5%, more preferably at least 6%, more preferably at least 7%, further preferably at least 8%, particularly preferably at least 10%, most preferably at least 12%. On the other hand, in order to improve the weather resistance, it is more preferably at most 18%, further preferably at most 16%, still more preferably at most 15%, particularly preferably at most 14.5%.

RO is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 7%, particularly preferably at least 10%, most preferably at least 12%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, it is more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 15%.

The glass plate according to embodiment 7 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

1.44≤Al₂O₃≤9

0.5≤B₂O₃≤13

0≤MgO≤15

0≤CaO≤20

0≤SrO≤15

0≤BaO≤1

0.01≤Li₂O≤1 9.1

0≤Na₂O≤16

0.9≤K₂O≤16

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

0.91≤R₂O≤20

0≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

10 ≤7Al₂O₃+3MgO-4Li₂O≤66

0≤Na₂O/R₂O≤0.8

0≤PbO<0.001

0≤ZnO≤3.

Within the range of the embodiment 7, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 7, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, more preferably at least 62%, further preferably at least 64%, particularly preferably at least 65%. With a view to improving the viscosity, it is more preferably at most 73%, further preferably at most 71%, still more preferably at most 70%, particularly preferably at most 68%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 1%, further preferably at least 1.5%, particularly preferably at least 2%, even more preferably at least 2.5%, still even more preferably at least 3%, most preferably at least 4%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 15%, further preferably at most 14%, particularly preferably at most 13%, even more preferably at most 12%, still even more preferably at most 10%, most preferably at most 8%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 0.5%, more preferably at least 1%, further preferably at least 1.5%, particularly preferably at least 2%, even more preferably at least 3%, most preferably at least 4%. Further, the K₂O content is more preferably at most 15%, further preferably at most 13%, particularly preferably at most 12%, even more preferably at most 10%, most preferably at most 8%.

The Li₂O content is, in order to increase the melting property and the Young's modulus and to improve the radio transmittance, more preferably at least 1%, further preferably at least 2%, particularly preferably at least 3%, even more preferably at least 4%. Further, Li₂O if contained may cause devitrification and phase separation, and accordingly its content is more preferably at most 15%, further preferably at most 12%, particularly preferably at most 10%, even more preferably at most 8%, most preferably at most 6%.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 6%, most preferably at most 4%.

7Al₂O₃+3MgO-4Li₂O is, in order to increase the radio transmittance, more preferably at least 11, further preferably at least 13, particularly preferably at least 15, even more preferably at least 17, most preferably at least 19. Further, the range of 7Al₂O₃+3MgO-4Li₂O is more preferably at most 60, further preferably at most 50, particularly preferably at most 45, even more preferably at most 40, most preferably at most 35.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at last 0.15, even more preferably at least 0.2, still even more preferably at least 0.25, most preferably at least 0.3. Further, Na₂O/R₂O is more preferably at most 0.85, further preferably at most 0.8, particularly preferably at most 0.6, even more preferably at most 0.5, most preferably at most 0.4.

In the embodiment 7, in order to lower the glass viscosity at the time of melting/forming for easy production, SiO₂+Al₂O₃ is preferably at least 50, further preferably at least 55, particularly preferably at least 60, even more preferably at least 65, most preferably at least 67. Further, SiO₂+Al₂O₃ is preferably at most 75, further preferably at most 74, particularly preferably at most 73, even more preferably at most 72, most preferably at most 71.

In order to lower the glass viscosity at the time of melting/forming for easy production, and to increase the radio transmittance, the Al₂O₃ content is preferably at most 9%. The Al₂O₃ content is more preferably at most 8%, further preferably at most 7%, particularly preferably at most 6%, even more preferably at most 5%. Further, the Al₂O₃ content is, in order to secure the weather resistance, more preferably at least 1.5%, further preferably at least 2%, particularly preferably at least 2.5%.

K₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, still even more preferably at least 0.25, most preferably at least 0.30. Further, K₂O/R₂O is more preferably at most 0.95, further preferably at most 0.8, particularly preferably at most 0.7, even more preferably at most 0.6, still even more preferably at most 0.5, most preferably at most 0.4.

In the embodiment 7, R₂O×MgO is more preferably lower so as to increase the radio transmittance. R₂O×MgO is preferably at most 200%², more preferably at most 180%², further preferably at most 160%², particularly preferably at most 140%², even more preferably at most 120%², still even more preferably at most 100%², most preferably at most 80%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 25%. It is more preferably at most 23%, further preferably at most 20%, even more preferably at most 18%, most preferably at most 16%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is preferably at most 13%, more preferably at most 12%, further preferably at most 10%, even more preferably at most 8%, most preferably at most 6%. Further, with a view to improving the melting property, the B₂O₃ content is preferably at least 0.5%, more preferably at least 1%, further preferably at least 1.5%, particularly preferably at least 2%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is preferably at most 15%, more preferably at most 14%, further preferably at most 13%, even more preferably at most 12%, most preferably at most 10%. Further, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 5%, most preferably at least 6%.

Further, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, the BaO content is preferably at most 1%, more preferably at most 0.5%, further preferably at most 0.1%, particularly preferably substantially no BaO is contained.

In the same manner as above, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, SrO+BaO+ZrO₂ is preferably at most 10%, more preferably at most 8%, further preferably at most 6%, particularly preferably at most 5%, even more preferably at most 4%, most preferably at most 3%.

Further, in order to increase the radio transmittance, the MgO content is more preferably at most 10%, further preferably at most 8%, particularly preferably at most 6%, even more preferably at most 4.5%, still even more preferably at most 3%, most preferably at most 2%.

In order to improve the melting property and to increase the radio transmittance, the CaO content is more preferably at least 0.5%. The CaO content is more preferably at least 1%, further preferably at least 3%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 7%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 15%, particularly preferably at most 14%, even more preferably at most 12%, most preferably at most 10%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, the ZrO₂ content is more preferably at most 1.8%, further preferably at most 1.5%.

The R₂O content is, with a view to improving the melting property, more preferably at least 5%, more preferably at least 6%, further preferably at least 7%, particularly preferably at least 8%, and on the other hand, in order to improve the weather resistance, more preferably at most 18%, further preferably at most 17%, still more preferably at most 16%, particularly preferably at most 15%, most preferably at most 14%.

The RO content is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 7%, particularly preferably at least 10%, and on the other hand, with a view to improving the weather resistance and suppressing devitrification, more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 15%, most preferably at most 13%.

The glass plate according to the present embodiment may contain ZnO which has an effect to suppress devitrification. If ZnO is contained in a large amount, defects may occur at the time of production in a float bath, and accordingly the ZnO content is preferably at most 3%. The ZnO content is more preferably at most 2%, more preferably at most 1.5%, further preferably at most 1%, and preferably substantially no ZnO is contained.

The glass plate according to embodiment 8 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

1≤Al₂O₃≤7.8

0.5≤B₂O₃≤15

0≤MgO≤11.8

2≤CaO≤20

0≤SrO≤15

0≤BaO≤1

4.25≤Li₂O≤19.15

0.25≤Na₂O≤15.15

0.60≤K₂O≤15.5

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

5.10≤R₂O≤20

2≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

−10 ≤7Al₂O₃+3MgO−4Li₂O≤10

0.05≤Na₂O/R₂O≤0.95

0.11≤K₂O/R₂O≤0.9

0≤PbO≤0.001.

Within the range of the embodiment 8, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 8, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 63%, particularly preferably at least 65%. With a view to improving the viscosity, it is more preferably at most 73%, further preferably at most 72%, particularly preferably at most 70%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 2%, further preferably at least 4%, particularly preferably at least 5%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 15%, further preferably at most 13%, particularly preferably at most 11%, even more preferably at most 10%, most preferably at most 8%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 1.0%, further preferably at least 2%, particularly preferably at least 4%, even more preferably at least 5%. Further, the K₂O content is more preferably at most 15%, further preferably at most 14%, particularly preferably at most 12%, even more preferably at most 10%, most preferably at most 8%.

The Li₂O content is, in order to increase the melting property and the Young's modulus and to improve the radio transmittance, more preferably at least 4.5%, further preferably at least 5.0%, particularly preferably at least 5.5%, even more preferably at least 6.0%. Further, Li₂O if contained may cause devitrification and phase separation, and accordingly its content is more preferably at most 15%, more preferably at most 12%, more preferably at most 10%, further preferably at most 9%, particularly preferably at most 8%, even more preferably at most 7%, most preferably at most 6%.

7Al₂O₃+3MgO-4Li₂O is, in order to increase the radio transmittance, more preferably at least −9, further preferably at least −6, particularly preferably at least −4, even more preferably at least −2, most preferably at least −1. Further, 7Al₂O₃+3MgO-4Li₂O is more preferably at most 9, further preferably at most 8, particularly preferably at most 7, even more preferably at most 6, most preferably at most 5.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 6%, most preferably at most 4%.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.1, further preferably at least 0.15, particularly preferably at least 0.2, even more preferably at least 0.25, most preferably at least 0.3. Further, Na₂O/R₂O is more preferably at most 0.9, further preferably at most 0.8, particularly preferably at most 0.7, even more preferably at most 0.6, still even more preferably at most 0.5, most preferably at most 0.4.

In the embodiment 8, SiO₂+Al₂O₃ is more preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, most preferably at least 68. Further, SiO₂+Al₂O₃ is more preferably at most 80%, further preferably at most 78%, particularly preferably at most 75%, even more preferably at most 74%, still even more preferably at most 73%, most preferably at most 72%.

In order to lower the glass viscosity at the time of melting/forming for easy production, and to increase the radio transmittance, the Al₂O₃ content is preferably at most 7%. The Al₂O₃ content is further preferably at most 6%, particularly preferably at most 5%, most preferably at most 4%. The Al₂O₃ content is, to secure the weather resistance, more preferably at least 1.5%, further preferably at least 2%, particularly preferably at least 2.5%.

K₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.15, further preferably at least 0.2, particularly preferably at least 0.25, even more preferably at least 0.28, most preferably at least 0.3. Further, K₂O/R₂O is more preferably at most 0.85, further preferably at most 0.8, particularly preferably at most 0.7, even more preferably at most 0.5, most preferably at most 0.4. By Na₂O/R₂O and K₂O/R₂O being within the predetermined ranges, the radio transmittance is likely to be increased.

In the embodiment 8, R₂O×MgO is more preferably low so as to increase the radio transmittance. R₂O×MgO is preferably at most 200%², more preferably at most 150%², further preferably at most 100%², particularly preferably at most 60%², even more preferably at most 50%², still even more preferably at most 40%², most preferably at most 30%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 25%, more preferably at most 22%, further preferably at most 20%, even more preferably at most 19%, most preferably at most 18%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 10%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is more preferably at most 12%, further preferably at most 8%, even more preferably at most 6%, most preferably at most 5%. Further, in order to improve the melting property, the B₂O₃ content is preferably at least 0.5%. The B₂O₃ content is more preferably at least 1%, further preferably at least 2%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, the range of MgO+CaO is preferably at most 15%, more preferably at most 14%, further preferably at most 13%, even more preferably at most 12%, most preferably at most 10%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

Further, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, the BaO content is preferably at most 1%, more preferably at most 0.5%, further preferably at most 0.1%, particularly preferably substantially no BaO is contained.

In the same manner as above, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, SrO+BaO+ZrO₂ is more preferably at most 12%, further preferably at most 8%, particularly preferably at most 5%, even more preferably at most 4%, most preferably at most 3%.

Further, in order to increase the radio transmittance, the MgO content is preferably at most 11.8%, more preferably at most 10%, further preferably at most 8%, particularly preferably at most 6%, even more preferably at most 4%, most preferably at most 2%.

In order to improve the melting property and to increase the radio transmittance, the CaO content is preferably at least 2%, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 16%, particularly preferably at most 14%, even more preferably at most 12%, still even more preferably at most 10%, still even more preferably at most 9%, most preferably at most 8%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, its content is more preferably at most 1.8%, further preferably at most 1.5%.

The R₂O content is, with a view to improving the melting property, more preferably at least 6%, further preferably at least 7%, particularly preferably at least 8%. On the other hand, in order to improve the weather resistance, it is more preferably at most 18%, further preferably at most 16%, still more preferably at most 15%, even more preferably at most 14.5%, particularly preferably at most 13.5%.

The RO content is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 4%, further preferably at least 6%, particularly preferably at least 7%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, it is preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, still more preferably at most 16%, particularly preferably at most 14%, most preferably at most 12%.

The glass plate according to embodiment 9 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

0.5≤A203 ≤15

0≤B₂O₃≤15

0≤MgO≤15

0≤CaO≤20

0≤SrO≤15

0≤BaO≤15

3.4<Li₂O≤20

0≤Na₂O≤16.6

0≤K₂O≤16.6

0≤ZrO₂≤2

0.001≤Fe₂O₃≤5

0.001≤TiO₂≤5

3.4≤R₂O≤20

1≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

−60 ≤7Al₂O₃+3MgO-4Li₂O≤−10

0≤PbO<0.001.

Within the range of the embodiment 9, a glass plate having a high radio transmittance and satisfying properties required for the desired application can be obtained.

In order to increase the radio transmittance, in the embodiment 9, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 63%, particularly preferably at least 65%. With a view to improving the viscosity, it is more preferably at most 74%, further preferably at most 72%, particularly preferably at most 70%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 1%, further preferably at least 2%, particularly preferably at least 3%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 15%, further preferably at most 13%, particularly preferably at most 11%, even more preferably at most 9%, most preferably at most 7%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 2%, even more preferably at least 3%, most preferably at least 4%. Further, the K₂O content is more preferably at most 15%, further preferably at most 13%, particularly preferably at most 11%, even more preferably at most 9%, most preferably at most 7%.

The Li₂O content is, in order to increase the melting property and the Young's modulus and to improve the radio transmittance, more preferably at least 3.5%, further preferably at least 4%, particularly preferably at least 4.5%, even more preferably at least 5%. Further, Li₂O if contained may cause devitrification and phase separation, and accordingly its content is more preferably at most 18%, further preferably at most 16%, particularly preferably at most 14%, even more preferably at most 13%, still even more preferably at most 12%, most preferably at most 10%.

SrO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where SrO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The SrO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 8%, even more preferably at most 6%, most preferably at most 4%.

7Al₂O₃+3MgO-4Li₂O is, in order to improve the water resistance of the glass, more preferably at least −50, further preferably at least −40, particularly preferably at least −35, even more preferably at least −30, most preferably at least −25. Further, in order to increase the radio transmittance of the glass, 7Al₂O₃+3MgO-4Li₂O is more preferably at most 11, further preferably at most −12, particularly preferably at most −13, even more preferably at most −14, most preferably at most −15.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, most preferably at least 0.25. Further, Na₂O/R₂O is more preferably at most 0.95, further preferably at most 0.9, particularly preferably at most 0.8, even more preferably at most 0.7, still even more preferably at most 0.6, most preferably at most 0.5.

In the embodiment 9, in order to lower the viscosity at the time of glass melting/forming for easy production, SiO₂+Al₂O₃ is preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, most preferably at least 68%. Further, the range of SiO₂+Al₂O₃ is preferably at most 80%, further preferably at most 78%, particularly preferably at most 76%, even more preferably at most 74%, most preferably at most 72%.

In order to lower the glass viscosity at the time of melting/forming for easy production, the Al₂O₃ content is more preferably at most 13%. The Al₂O₃ content is further preferably at most 11%, particularly preferably at most 9%, even more preferably at most 7%, most preferably at most 5%. The Al₂O₃ content is, in order to secure the weather resistance, more preferably at least 1%, further preferably at least 1.5%, particularly preferably at least 2%, especially particularly preferably at least 2.5%, most preferably at least 3%.

K₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.05, further preferably at least 0.1, particularly preferably at least 0.15, even more preferably at least 0.2, most preferably at least 0.25. Further, K₂O/R₂O is more preferably at most 0.95, further preferably at most 0.9, particularly preferably at most 0.7, even more preferably at most 0.5, most preferably at most 0.4. By Na₂O/R₂O and K₂O/R₂O being within the predetermined ranges, the radio transmittance is likely to be increased.

In the embodiment 9, R₂O×MgO is more preferably low so as to increase the radio transmittance. R₂O×MgO is more preferably at most 200%², further preferably at most 100%², particularly preferably at most 70%², even more preferably at most 50%², most preferably at most 30%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 25%, more preferably at most 24%, more preferably at most 23%, further preferably at most 21%, even more preferably at most 19%, most preferably at most 18%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 1%, more preferably at least 2%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 8%.

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, the B₂O₃ content is preferably at most 15%, more preferably at most 12%, further preferably at most 10%, even more preferably at most 8%, most preferably at most 6%. Further, B₂O₃ may be contained so as to improve the melting property, and in a case where B₂O₃ is contained, its content is preferably at least 0.5%, more preferably at least 1%, further preferably at least 2%.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, in a case where MgO and CaO are contained, MgO+CaO is preferably at most 15%, more preferably at most 14%, further preferably at most 13%, even more preferably at most 12%, most preferably at most 10%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 2%, further preferably at least 3%, even more preferably at least 4%, most preferably at least 5%.

Further, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, the BaO content is preferably at most 15%, more preferably at most 10%, further preferably at most 8%, particularly preferably at most 5%, even more preferably at most 3%, still even more preferably at most 1%, most preferably substantially no BaO is contained.

In the same manner as above, in order to prevent the glass from being fragile and having lowered strength, or for weight saving of the glass plate, SrO+BaO+ZrO₂ is more preferably at most 12%, further preferably at most 8%, particularly preferably at most 6%, even more preferably at most 4%, most preferably at most 2%.

Further, in order to increase the radio transmittance, the MgO content is more preferably at most 12%. The MgO content is further preferably at most 8%, particularly preferably at most 5%, even more preferably at most 3%, most preferably at most 2%.

In order to improve the melting property and to increase the radio transmittance, the CaO content is more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 2%, even more preferably at least 3%, most preferably at least 4%. The CaO content is, with a view to suppressing devitrification, more preferably at most 15%, further preferably at most 13%, particularly preferably at most 11%, even more preferably at most 9%, most preferably at most 8%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. In order that the average coefficient of linear expansion is not high, the content is more preferably at most 1.8%, further preferably at most 1.5%.

The R₂O content is, with a view to improving the melting property, more preferably at least 5%, more preferably at least 6%, more preferably at least 7%, further preferably at least 8%, particularly preferably at least 10%. On the other hand, in order to improve the weather resistance, the R₂O content is more preferably at most 18%, further preferably at most 17%, even more preferably at most 15%, particularly preferably at most 14.5%.

The RO content is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 5%, further preferably at least 7%, particularly preferably at least 10%, most preferably at least 12%, and on the other hand, with a view to improving the weather resistance and suppressing devitrification, more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 15%.

The glass plate according to embodiment 10 of the present invention preferably satisfies the following conditions.

It contains, as represented by mol % based on oxides, the following components in the following contents:

55≤SiO₂≤75

0≤Al₂O₃<1.3

0≤B₂O₃≤15

0≤MgO≤4.5

0≤CaO≤20

0≤SrO≤4

0≤BaO≤15

0Li₂O<0.01

0≤Na₂O≤14.4

1≤K₂O≤16

0ZrO₂c2

0.001≤Fe₂O₃≤1.5

0.001≤TiO₂≤5

1.1≤R₂O≤18

0≤RO≤20

85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100

0 ≤7Al₂O₃+3MgO≤22.6

0.05≤Na₂O/R₂O≤0.80

0≤PbO<0.001

0≤ZnO≤0.5.

Within the range of the embodiment 10, a glass plate which has a high radio transmittance, mass production of which by float process is easily conducted, and which satisfies properties required for the desired application, can be obtained.

In order to increase the radio transmittance, in the embodiment 10, the following range is more preferred.

The SiO₂ content is, in order to increase the Young's modulus and the weather resistance, more preferably at least 60%, further preferably at least 65%, still more preferably at least 68%, particularly preferably at least 70%. With a view to improving the viscosity, the SiO₂ content is more preferably at most 74%, further preferably at most 73.5%, particularly preferably at most 73%.

Al₂O₃ is, in order to increase the radio transmittance, more preferably less than 1.3%, more preferably at most 1.2%, further preferably at most 1.0%, particularly preferably at most 0.8%. In order to increase the Young's modulus and the weather resistance, more preferably at least 0.1%, further preferably at least 0.2%, particularly preferably at least 0.3%, most preferably at least 0.5%.

The MgO content is, with a view to improving the melting property and the weather resistance, more preferably at least 0.1%, further preferably at least 0.25%, still more preferably at least 0.3%, still more preferably at least 0.4%, particularly preferably at least 0.5%. The MgO content is, in order to increase the radio transmittance, more preferably at most 4.5%, more preferably at most 4.0%, more preferably at most 3.5%, further preferably at most 3%, still more preferably at most 2.5%, even more preferably at most 2%, particularly preferably at most 1.5%, most preferably at most 1%.

The CaO content is, in order to improve the melting property and to increase the radio transmittance, preferably at least 1%, more preferably at least 2%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 8%. The CaO content is, with a view to suppressing devitrification, more preferably at most 18%, further preferably at most 16%, particularly preferably at most 15%, even more preferably at most 14%, most preferably at most 13%.

BaO may be contained so as to improve the melting property and to increase the radio transmittance, and in a case where BaO is contained, its content is preferably at least 0.5%, more preferably at least 1%, particularly preferably at least 2%. The BaO content is, in order to prevent the glass from being fragile, more preferably at most 12%, further preferably at most 10%, particularly preferably at most 7%, especially particularly preferably at most 5%, most preferably at most 3%.

The Na₂O content is, in order to increase the melting property and to adjust the average coefficient of linear expansion, more preferably at least 0.1%, further preferably at least 1%, particularly preferably at least 3%, even more preferably at least 5%, still even more preferably at least 6%, most preferably at least 7%. Further, Na₂O if contained deteriorates the weather resistance, and accordingly its content is more preferably at most 13%, further preferably at most 11%, particularly preferably at most 10%, even more preferably at most 9%, most preferably at most 8%.

The K₂O content is, in order to increase the radio transmittance, more preferably at least 3%, further preferably at least 4%, particularly preferably at least 5%, even more preferably at least 6%, most preferably at least 7%. In order that the high temperature viscosity is not too high, it is more preferably at most 13%, further preferably at most 11%, particularly preferably at most 10%, even more preferably at most 9%, most preferably at most 8%.

ZrO₂ may be contained so as to improve the chemical durability, and in a case where ZrO₂ is contained, its content is more preferably at least 0.5%. The ZrO₂ content is, in order that the average coefficient of linear expansion is not high, more preferably at most 1.8%, further preferably at most 1.5%.

R₂O is, with a view to improving the melting property, more preferably at least 4%, more preferably at least 5%, further preferably at least 6%, still more preferably at least 7%, particularly preferably at least 8%. On the other hand, in order to improve the weather resistance, it is more preferably at most 17%, further preferably at most 15%, still more preferably at most 14%, particularly preferably at most 13%, particularly preferably at most 12%, especially particularly preferably at most 11%, most preferably at most 10%.

RO is, with a view to improving the melting property and improving the radio transmittance, more preferably at least 4%, more preferably at least 5%, further preferably at least 7%, particularly preferably at least 10%, especially particularly preferably at least 12%, most preferably at least 12.5%. On the other hand, with a view to improving the weather resistance and suppressing devitrification, it is more preferably at most 19%, further preferably at most 18%, still more preferably at most 17%, particularly preferably at most 16%, most preferably at most 15%.

7Al₂O₃+3MgO is, in order to increase the weather resistance and to increase the Young's modulus thereby to increase rigidity of the glass plate, more preferably at least 0.5%, further preferably at least 1%, particularly preferably at least 2%, even more preferably at least 3%, most preferably at least 5%. Further, in order to increase the radio transmittance, 7Al₂O₃+3MgO is more preferably at most 22%, further preferably at most 20%, particularly preferably at most 18%, even more preferably at most 15%, most preferably at most 10%.

Na₂O/R₂O is, in order to increase the radio transmittance, more preferably at least 0.1, more preferably at least 0.2, more preferably at least 0.25, further preferably at least 0.3, particularly preferably at least 0.35, even more preferably at least 0.4, most preferably at least 0.45. Further, Na₂O/R₂O is more preferably at most 0.75, further preferably at most 0.7, particularly preferably at most 0.65, even more preferably at most 0.6, most preferably at most 0.55.

SiO₂+Al₂O₃ is more preferably at least 50%, further preferably at least 55%, particularly preferably at least 60%, even more preferably at least 65%, most preferably at least 68%. Further, SiO₂+Al₂O₃ is more preferably at most 80%, further preferably at most 78%, particularly preferably at most 76%, even more preferably at most 74.5%, still even more preferably at most 74%, most preferably at most 73%.

R₂O×MgO is more preferably lower so as to increase the radio transmittance. R₂O×MgO is preferably at most 80%², more preferably at most 75%², further preferably at most 70%², particularly preferably at most 50%², even more preferably at most 30%², most preferably at most 20%^(2·)

In order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, R₂O+B₂O₃ is preferably at most 19%, more preferably at most 18%, further preferably at most 17%, even more preferably at most 16%, most preferably at most 15%. However, if R₂O+B₂O₃ is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, R₂O+B₂O₃ is preferably at least 2%, more preferably at least 4%, more preferably at least 6%, further preferably at least 8%, even more preferably at least 10%, most preferably at least 12%.

In the embodiment 10 also, in order to prevent boron and alkali elements from volatilizing during melting/forming, thus leading to deterioration of the glass quality, by a relative increase of the Na₂O content in the glass to the total alkali amount, particularly in production by float process, the B₂O₃ content is preferably at most 15%, more preferably at most 10%, further preferably at most 7%, even more preferably at most 5%, still even more preferably at most 3%, particularly preferably at most 2%, especially particularly preferably at most 1%, most preferably substantially no B₂O₃ is contained.

The glass plate according to the embodiment 10 preferably satisfies 85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100, whereby a glass plate can be produced from easily available glass raw materials. Further, in the case of a composition with small Al₂O₃ and MgO as the glass of the present embodiment, in order to secure also the weather resistance of the glass plate, the above total amount is more preferably at least 98.5%. It is more preferably at least 99%, particularly preferably at least 99.5%. Since a glass plate for a window material typically contains a coloring agent, a fining agent, etc., the upper limit of the total amount is even more preferably 99.9%.

Further, in the embodiment 10, in order to prevent the glass from being fragile and having lowered strength, since the amounts of Al₂O₃ and MgO are small, and for weight saving of the glass plate, the SrO content is preferably at most 4%, more preferably at most 2.5%, further preferably at most 1%, and particularly preferably substantially no SrO is contained.

In order to prevent occurrence of devitrification at the time of glass melting/forming, thus leading to deterioration of the glass quality, MgO+CaO is preferably at most 18%, more preferably at most 16%, more preferably at most 14%, further preferably at most 13%, even more preferably at most 12%, most preferably at most 11%. However, if MgO+CaO is too low, the glass viscosity at the time of melting/forming may be too high, whereby glass production may be difficult. Accordingly, MgO+CaO is preferably at least 1%, more preferably at least 3%, further preferably at least 4%, even more preferably at least 6%, most preferably at least 9%.

The glass plate according to the embodiment 10 particularly tends to be devitrified. Accordingly, the TiO₂ content is preferably at most 1.5%, more preferably at most 1%, further preferably at most 0.5%, particularly preferably at most 0.2%, even more preferably at most 0.1%, most preferably at most 0.05%.

In order that the glass plate according to the embodiment 10 can be produced by float process, the ZnO content is preferably at most 0.5%. ZnO if contained forms a Zn-based compound in a float bath, thus leading to glass defects. Accordingly, the ZnO content is more preferably at most 0.1%, further preferably ZnO is not contained.

Of the glass plate according to the present embodiment, the Fe₂O₃ content is preferably from 0.001% to 1.5%. If the Fe₂O₃ content is less than 0.001%, the glass plate may not be used for an application for which heat shielding property is required, it is necessary to use an expensive raw material having a low iron content for production of the glass plate, and further, thermal radiation may reach the bottom of the melting furnace more than necessary at the time of glass melting and a burden may be imposed on the melting furnace. The Fe₂O₃ content is more preferably at least 0.005%, further preferably at least 0.01%, particularly preferably at least 0.015%, even more preferably at least 0.02%, most preferably at least 0.05%.

If the Fe₂O₃ content is higher than 1.5%, heat transfer by radiation may be inhibited, whereby the raw materials may not easily be melted. Further, if the Fe₂O₃ content is too high, the light transmittance in the visible region decreases (T_(V) decreases), and such a glass plate may not be suitable for an application to automobiles. Accordingly, the Fe₂O₃ content is more preferably at most 1.5%, further preferably at most 1%, further preferably at most 0.8%, still more preferably at most 0.6%, particularly preferably at most 0.5%, even more preferably at most 0.4%, most preferably at most 0.3%.

Of the glass plate in the present invention, according to any of the above embodiments, the NiO content is preferably at most 100 mass ppm (including 0 mass ppm). Of the glass plate of the present invention, the total content of components other than SiO₂, Al₂O₃, B₂O₃, MgO, CaO, SrO, BaO, Li₂O, Na₂O, K₂O, TiO₂, ZrO₂, Fe₂O₃ and NiO (hereinafter sometimes referred to as “other components”) is preferably at most 5%. Such other components may, for example, be Y₂O₃, Nd₂O₅, P₂O₅, GaO₂, GeO₂, CeO₂, MnO₂, CoO, Cr₂O₃, V₂O₅, Se, Au₂O₃, Ag₂O, ZnO, CuO, CdO, SO₃, Cl, F, SnO₂ and Sb₂O₃, and they may be in the form of metal ions or may be in the form of an oxide. Of the glass plate of the present invention, more preferably the NiO content is at most 100 mass ppm (including 0 mass ppm) and the total content of other components is at most 5%.

NiO if contained forms NiS, which may lead to glass destruction, and accordingly its content is preferably at most 100 mass ppm, more preferably at most 10 mass ppm, and further preferably substantially no NiO is contained. Other components may be contained in a content of at most 5% for various purposes (for example, fining and coloring). If the content of other components is higher than 5%, the radio transmittance may be negatively affected. The content of other components is more preferably at most 3%, more preferably at most 2%, further preferably at most 1.5%, further preferably at most 1%, particularly preferably at most 0.5%, even more preferably at most 0.3%, most preferably at most 0.1%. Further, in order to prevent influence over the environment and human body, the As₂O₃ and PbO contents are respectively preferably less than 0.001%, and most preferably substantially no As₂O₃ and PbO are contained.

SO₃ may be used as a fining agent and contribute to degassing. In a case where SO₃ is used, it may be contained in the glass by using a sulfate as a raw material, and in a case where SO₃ is contained, its content is preferably at least 0.01%, more preferably at least 0.02%, more preferably at least 0.04%, particularly preferably at least 0.08%, most preferably at least 0.1%. If it is contained in a large amount, the above-described amber coloring may occur, and accordingly its content is preferably at most 1%, more preferably at most 0.8%, still more preferably at most 0.6%, most preferably at most 0.5%.

Sb₂O₃ acts as a fining agent in the same manner as SO₃, and in order to prevent influence over the environment and human body, its content is more preferably at most 0.5%, further preferably at most 0.2%, still more preferably at most 0.1%, particularly preferably at most 0.05%, especially particularly preferably at most 0.01%, and most preferably substantially no Sb₂O₃ is contained.

CeO₂ acts as an oxidizing agent to control the FeO amount. Further, it blocks ultraviolet light to prevent deterioration of an interior material by ultraviolet light. In a case where CeO₂ is contained, its content is preferably at least 0.004%, more preferably at least 0.01%, further preferably at least 0.05%, particularly preferably at least 0.1%. In order to prevent the cost increase at the time of production, it is preferably at most 1%, more preferably at most 0.5%, particularly preferably at most 0.3%.

Cr₂O₃ acts as an oxidizing agent to control the FeO amount. In a case where Cr₂O₃ is contained, its content is preferably at least 0.002%, more preferably at least 0.004%. Cr₂O₃ has coloring in the visible region and thus may decrease the transmittance in the visible region. The content is preferably at most 1%, more preferably at most 0.5%, particularly preferably at most 0.3%, most preferably at most 0.1%.

SnO₂ functions as a reducing agent to control the FeO amount. In a case where SnO₂ is contained, its content is preferably at least 0.01%, more preferably at least 0.04%, further preferably at least 0.06%, particularly preferably at least 0.08%. In order to suppress defects derived from SnO₂ at the time of production, its content is preferably at most 1%, more preferably at most 0.5%, particularly preferably at most 0.3%, most preferably at most 0.2%.

Further, P₂O₅ is likely to generate glass defects in a float bath in production by float process, and accordingly its content is more preferably at most 1%, further preferably at most 0.5%, particularly preferably at most 0.1%, even more preferably less than 0.001%.

The glass plate of the present invention preferably has a dielectric loss tanδ at a frequency of 35 GHz of at least 0.001 and at most 0.019. The dielectric loss tanδ of the glass material is particularly preferably low, whereby the radio transmittance can be increased. tanδ is preferably at most 0.019, more preferably at most 0.017, further preferably at most 0.015, particularly preferably at most 0.013, even more preferably at most 0.010, most preferably at most 0.008. In view of the radio transmittance, there is no lower limit of the preferred dielectric loss, however, if tanδ is too low, the SiO₂ content tends to be too high, and the glass melting property may decrease. Accordingly, tanδ is preferably at least 0.0015, more preferably at least 0.003, further preferably at least 0.004, particularly preferably at least 0.005, even more preferably at least 0.007, most preferably at least 0.0075.

The glass plate of the present invention has a thickness of preferably at least 1 mm and at most 36 mm. If the thickness is less than 1 mm, the glass plate is less likely to have rigidity and may hardly be practically used. The thickness of the glass plate of the present invention is more preferably at least 1.2 mm, further preferably at least 1.8 mm, particularly preferably at least 2.4 mm, even more preferably at least 2.8 mm, most preferably at least 3.7 mm. Further, if the thickness exceeds 36 mm, advantageous of the material having a high radio transmittance may not practically sufficiently be made use of. The thickness is more preferably at most 24 mm, further preferably at most 12 mm, particularly preferably at most 10 mm, even more preferably at most 8 mm, most preferably at most 7 mm.

The thickness may be a total thickness of a plurality of glass plates overlaid. For examples, two different glass plates of the present invention may be laminated to have the above thickness. The glass plate of the present invention may be used together with another glass plate, that is, as overlaid on or disposed to be adjacent to another glass plate. The above-described glass plate having a specific composition may secure the radio transmittance as defined in this specification, even when overlaid on a glass plate having a composition out of the range of the specific composition. That is, only one or some layers in laminated glass may have the above specific composition. The glass plate of the present invention may be used as laminated on a transparent resin other than glass.

In another aspect of the present invention, a window comprising the glass plate according to the above embodiment is provided.

In this specification, a “window” means one comprising a see-through glass plate to partition the interior and the exterior of a vehicle or a building or one room and an adjacent room, surrounded by a non-glass material. The “vehicle” includes any vehicle and transport having a room surrounded by a wall (which may include a window), such as an automobile, a train, a carriage, ship, an airplane, a helicopter, a cable car, a Ferris wheel, etc. Likewise, the “building” includes any building having a room surrounded by a wall (which may include a window), such as a house, an office building, a store, a warehouse, a factory, a booth, etc. The non-glass material surrounding the glass plate in the window may, for example, be a metal, a wood material, a concrete, a stone material, a ceramic, bricks, plastic, carbon fibers, or any mixture thereof, but it is not limited thereto. The non-glass material surrounding the glass plate is typically a body frame or a door frame of an automobile, or a material of a wall, a ceiling, a floor or a door, or a window frame, of a building. It is possible that the entire door, the entire wall, the entire ceiling or the entire floor may comprise a window.

The glass plate which the window of the present invention comprises usually has an area of at least 10,000 mm² per plate, however, a window constituted by a plurality of glass plates having a smaller area is possible. The window by the present invention may comprise the glass plate of the present invention as laminated with other glass plate or a transparent material and embedded.

According to an embodiment, the window is a window for an automobile. That is, this window may be a windshield, a rear glass, a front door glass, a rear door glass, a side glass or a roof glass of an automobile. The thickness of the glass plate which the window for an automobile comprises is preferably at least 1.2 mm, more preferably at least 2 mm, further preferably at least 2.8 mm, even more preferably at least 3.2 mm, most preferably at least 3.7 mm. The visible light transmittance T_(VA) (JIS R3106: 1998) of the glass plate which the window for an automobile comprises, is preferably at least 72% as calculated as 3.85 mm thickness, in the case of a windshield or a front door glass. In applications other than a windshield or a front door glass, T_(VA) is usually from 30 to 92%.

According to an embodiment, the window for an automobile may be provided with an information acquisition apparatus to acquire information from outside by light irradiation and/or light receiving, has at least one information acquisition region which faces the information acquisition apparatus and which transmits light, and has an outside glass plate, an inside glass plate and an interlayer disposed between these glass plates. It is particularly preferably used for a windshield. The window for an automobile may be a laminated glass or may be tempered glass. The tempered glass may be physically tempered glass or may be chemically tempered glass.

The wavelength of light which is applied to or received by the window for an automobile is preferably within a range of from 700 to 1,650 nm, whereby a commercial laser radar or infrared camera can be used. Further, the transmittance of the information acquisition region at a wavelength of from 700 to 1,650 nm is preferably from 80 to 92%, whereby light detection by the information acquisition apparatus becomes easy. The transmittance is more preferably at least 83%, further preferably at least 86%, particularly preferably at least 88%, even more preferably at least 89%, most preferably at least 90%. Further, if the transmittance at a wavelength of from 700 to 1,650 nm is too high, the heat shielding property may be deteriorated, and accordingly the transmittance is more preferably at most 91.5%, further preferably at most 91%.

According to an embodiment, the window for an automobile may be provided with an information acquisition apparatus to acquire information from outside by light irradiation and/or light receiving, has at least one information acquisition region which faces the information acquisition apparatus and which transmits light, and has an outside glass plate, an inside glass plate and an interlayer disposed between these glass plates. It is particularly preferably used for a windshield.

The frequency of radio waves applied to or received by the window for an automobile is preferably within a range of from 2 to 100 GHz, whereby a commercial radar apparatus can be used. it is more preferably at least 20 GHz, further preferably at least 50 GHz, particularly preferably at least 60 GHz. Further, at least one of the outside glass plate and the inside glass plated to be used for the information acquisition region has a radio transmittance of preferably from 20 to 84% at a frequency of 100 GHz as calculated as 18 mm thickness, whereby radio detection by the information acquisition apparatus will be easy. The radio transmittance is more preferably at least 22%, further preferably at least 25%, still more preferably at least 29%, particularly preferably at least 33%, even more preferably at least 37%, most preferably at least 40%. Further, if the radio transmittance is too high, preparation of such glass is difficult, and accordingly it is more preferably at most 80%, more preferably at most 70%, more preferably at most 60%, further preferably at most 55%, still more preferably at most 50%, particularly preferably at most 45%, even more preferably at most 43%, most preferably at most 41%.

Further, according to an embodiment, it is more preferred that both light irradiation and/or light receiving, and radio irradiation and/or radio receiving, are possible.

Accordingly to an embodiment, the window is a window for a building material. That is, the window is disposed on a wall, a door, a ceiling, a roof or a floor of a building. The thickness of the glass plate which the window for a building material comprises, is preferably at least 2 mm, more preferably at least 4 mm, further preferably at least 6 mm, particularly preferably at least 8 mm, even more preferably at least 10 mm, most preferably at least 12 mm.

The glass plate according to the embodiment of the present invention, or the glass plate which the window according to the embodiment of the present invention comprises, has a length of preferably at least 30 mm in a radio polarization direction. The polarization direction may be a direction perpendicular to the vertical line and in parallel with the glass plate surface, or a direction in parallel with the vertical line and in parallel with the glass plate surface. For example, a glass plate disposed in a flat window placed perpendicular to the horizontal plane, may have the above length in a lateral (horizontal) direction or in a lengthwise (vertical) direction. When the glass plate has a sufficient length in a polarization direction, radio waves of a radar or a mobile phone are likely to be transmitted/received.

According to another aspect of the present invention, a radio communication apparatus comprising the glass plate according to the above embodiment is provided.

In this specification, the “radio communication apparatus” means an electronic apparatus medium utilizing radio communication. The “radio communication apparatus” may include a mobile phone, a tablet, a personal computer, a clock, glasses, etc. In this specification, the “radio communication apparatus” comprises a front member and a rear member, and the glass plate according to the embodiment may be used for at least part of the front member or the rear member. Further, typically, the radio communication apparatus has a body holding the front member and the rear member. It may have, in the interior surrounded by the front member, the rear member and the body, an element having display function, an electric circuit board to drive the element, etc. The element having display function may, for example, be a liquid crystal display device or an organic EL device. Information can be displayed by the element having display function at least on the front member side. Information may also be displayed by the element having display function also on the rear member side as the case requires. The front member and the rear member may have a shape corresponding to the application and may be flat or curved.

The front member and the rear member may have a hole for a speaker, an operation button, a camera lens or the like. Typically, the front member has a hole for a speaker and an operation button, and the rear member has a hole for a camera lens.

The material of the front member, the rear member and the body may, for example, be glass, crystallized glass, phase separated glass, a metal, a wood material, a stone material, a ceramic, a plastic, carbon fibers, a mixture of any of them, or a laminate of the combination of them.

The glass plate which the radio communication apparatus of the present invention comprises, may be laminated with other glass plate or transparent material and embedded. Further, it may be a chemically tempered glass plate.

The glass plate which the radio communication apparatus of the present invention comprises, may be used for both of the front member and the rear member of the radio communication apparatus, or may be used for only one of them.

The glass plate which the radio communication apparatus of the present invention comprises, has a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, and is thereby hardly a barrier to transmitting/receiving when the radio communication apparatus is used. In a case where the glass plate is provided to the radio communication apparatus, the radio transmittance is preferably at least 27%, more preferably at least 28%, further preferably at least 29%, particularly preferably at least 30%, most preferably at least 32%.

Further, in a case where the glass plate according to the embodiment is used for both the front member and the rear member, the difference between the radio transmittance of the glass plate used for the front member at a frequency of 100 GHz as calculated as 18 mm thickness and the radio transmittance of the glass plate used for the rear member at a frequency of 100 GHz as calculated as 18 mm thickness, is preferably at least 4%. When the difference in the radio transmittance is at least 4%, radio transmitting/receiving is carried out via the member having a higher radio transmittance between the front member and the rear member, and radio transmitting/receiving from the other member can be suppressed. For example, in a case where a speaker or a microphone is provided on the front member side, the front member side is used on the human head side, and by using the glass plate having a low radio transmittance on the front member side, radio waves which reach the human head can be weakened, and by using the glass plate having a high radio transmittance on the rear member side, radio transmitting/receiving can be conducted.

According to an embodiment, the radio communication apparatus has an antenna as a radio transmitting/receiving apparatus. The antenna may be disposed adjacent to or in contact with the glass plate, or may be formed in the glass plate, whereby the transmitting/receiving sensitivity of the antenna can be improved. Further, the antenna is preferably one capable of transmitting/receiving electromagnetic waves at a frequency of at least 1.0 GHz. The frequency of the radio waves transmitted/received by the antenna is preferably at least 2.4 GHz, more preferably at least 5 GHz, further preferably at least 10 GHz, particularly preferably at least 15 GHz, most preferably at least 25 GHz. There is no particular upper limit, and considering the application of the glass of the present invention, the frequency is at most 100 GHz, preferably at most 90 GHz.

According to an embodiment, the thickness of the glass plate which the radio communication apparatus comprises is, in a case where the glass plate is used for a part of or the entire rear member, preferably at most 4 mm, more preferably at most 2.5 mm, further preferably at most 1.5 mm, particularly preferably at most 1.1 mm, even more preferably at most 0.9 mm, most preferably at most 0.7 mm. On the other hand, the glass plate may have lowered strength if it is thin, and accordingly, the thickness is more preferably at least 0.5 mm. The thickness may not necessarily be uniform, may be distributed, and can be determined depending upon the application. If the thickness of the glass plate is distributed, the thickness at the thickest portion is defined as the “thickness of the glass plate” (the same applies in this specification).

Further, according to an embodiment, the thickness of the glass plate which the radio communication apparatus comprises is, when the glass plate is used for a part of or the entire front member, preferably at most 2.5 mm, more preferably at most 1.5 mm, further preferably at most 1.3 mm, particularly preferably at most 1.1 mm, even more preferably at most 0.9 mm, most preferably at most 0.7 mm. On the other hand, the glass plate may have lowered strength if it is thin, and accordingly the thickness is more preferably at least 0.5 mm. The thickness may not necessarily be uniform, may be distributed, and can be determined depending upon the application.

The visible light transmittance of the glass plate which the radio communication apparatus comprises may be adjusted depending upon the application, and the visible light transmittance of the glass plate used for a side on which information is displayed is more preferably at least 60% as calculated as 3.85 mm thickness.

EXAMPLES

Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples.

[Preparation of Glass Plate Sample]

A glass plate having a composition (unit: mol %) as identified in the following Tables 1-1 to 1-28 was produced by a common method known to those skilled in the art. Specifically, raw materials were put in a platinum crucible so as to achieve the identified glass composition and melted at 1,550° C. for 2 hours, the melt was cast on a carbon plate and annealed to obtain a plate of glass. Both surfaces of the obtained plate were polished to obtain a glass plate having a thickness of about 30 mm.

Methods to determine values shown in Tables 1-1 to 1-28 are shown below.

(1) Average coefficient of linear expansion (a) from 50 to 350° C.:

The average coefficient of linear expansion (a) was measured by a differential thermal dilatometer (TMA) and obtained as specified by JIS R3102 (1995).

(2) Glass transition point (Tg):

The glass transition point (Tg) was a value measured by TMA and determined by the specification of JIS R 3103-3 (2001).

(3) Specific gravity (d):

The specific gravity (d) was obtained by measuring about 20 g of a glass block containing no bubble, cut out from the glass plate, by Archimedes' principle.

(4) Viscosity:

The viscosity was measured by a rotation viscosimeter, and the temperature T₂ (standard temperature for melting property) when the viscosity η becomes 10² dPa·s, and the temperature T₄ (standard temperature for forming property) when the viscosity ri becomes 10⁴ dPa·s were measured.

(5) Liquid phase temperature (T_(L)):

Platinum dishes on which 5 g of a glass block cut out from the glass plate was put, were respectively put in electric furnaces at different temperatures higher than the glass transition point, held for 17 hours, taken out of the furnaces and cooled. Whether precipitation was observed or not on the surface and in the inside of the glass block after cooling was examined, and the minimum temperature after held for 17 hours, among temperatures when no crystal was precipitated, was taken as the liquid phase temperature.

-   -   (6) Young's modulus (E):

The Young's modulus (E) was measured by ultrasonic glass technique (Olympus Corporation, DL35) at 25° C.

(7) Water resistance:

It was measured as a Na₂O elution amount (mg) as specified by JIS R3502 (1995).

(8) Visible light transmittance (T_(VA)):

The glass plate was formed into a rectangle of 30.0 mm×30.0 mm×3.85 mm in thickness, and the 30.0 mm×30.0 mm faces were polished to mirror surface. The transmittance was measured by a spectrophotometer in accordance with JIS R3106: 1998, and the visible light transmittance T_(VA) was calculated. As the spectrophotometer, spectrophotometer U4100 manufactured by Hitachi High-Technologies Corporation was used. As the weighting factors, standard illuminant A, 2 degree field of view values are employed. The value is as calculated as 3.85 mm plate thickness.

The value as calculated as 3.85 mm plate thickness is a value (visible light transmittance T_(VA)) of the glass plate as calculated as 3.85 mm plate thickness, considering the multiple reflection, by the reflectance of the glass plate calculated by Sellmeier's equation from the refractive index of the glass plate the transmittance of which was measured.

Glass having a visible light transmittance T_(VA) of from 30 to 92% is represented by “◯”, and a glass having a visible light transmittance T_(VA) of higher than 92% or lower than 30% is represented by “×”.

(9) Solar direct transmittance (Te):

As for Te, the transmittance was measured in accordance with ISO-13837A: 2008 by a spectrophotometer, and the solar direct transmittance Te was calculated. It is represented by a value as calculated as 3.85 mm plate thickness.

A glass plate having a solar direct transmittance Te of from 35 to 91% is represented by “◯”, and a glass having a solar direct transmittance Te of higher than 91% or lower than 35% is represented by “×”.

(10) Ultraviolet transmittance (Tuv):

Tuv is as specified by ISO-9050: 2003.

(11) Transmittance at wavelength 905 nm, transmittance at wavelength 1,550 nm

They were measured by a spectrophotometer. They are represented by values as calculated as 3.85 mm plate thickness.

(12) FeO content

Ground glass was decomposed by a mixed acid of hydrofluoric acid and hydrochloric acid at room temperature, a certain amount of the decomposed liquid was collected in a plastic container, and a 2,2′-dipyridyl solution and an ammonium acetate buffer solution were quickly added for color development of only Fe²⁺. The color developer was diluted with deionized water for a certain amount, and the absorbance at a wavelength of 522 nm was measured by an absorptiometer. And, from an analytical curve prepared by using a standard solution, the concentration was calculated and the FeO amount was calculated. FeO in Tables is the FeO amount as calculated as Fe₂O₃.

(13) Radio Transmittance

The radio transmittance with 18 mm thickness at 100 GHz, the exponential approximation formula of relation between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1, and the exponential approximation formula of relation between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 were calculated from the above-described methods. The radio transmittance with 18 mm thickness at 100 GHz was obtained by carrying out exponential approximation as described above. The dielectric constant and the dielectric loss of the glass used for calculation were measured by cavity resonator method.

(14) Radio Transmitted Amount of Laminated Glass

Both surfaces of the glass plate were further polished to obtain a glass plate having a thickness of 2.0 mm. Two such glass plates having a thickness of 2.0 mm were laminated by means of a polyvinyl butyral (interlayer; PVB) adhesive layer and pre-bonded with vacuum suction, and the laminate was heated and pressurized by an autoclave chamber to obtain a laminated glass. The thickness of the adhesive layer in the obtained laminated glass was 0.7 mm.

The radio transmitted amount of the obtained laminated glass was measured by free space method. Antennas were disposed to face each other, the obtained laminated glass was disposed between them, and the radio transmitted amount of the laminated glass was measured based on a case where there is no laminated glass at an opening part having a diameter of 100 mm being 0 dB. The radio transmitted amount was measured at a frequency within a range of from 65 to 85 GHz.

FIG. 4 is a graph illustrating the measured value of the radio transmitted amount and the calculated value of the radio transmitted amount obtained by exponential approximation of the laminated glass in Comparative Example 1. Well agreement between the measured value and the calculated value was confirmed. The same calculation was conducted in Example 3, Example 4, Example 11 and Example 25. FIG. 5 is a graph illustrating the measured value of the radio transmitted amount and the calculated value of the radio transmitted amount obtained by exponential approximation of the laminated glass in each of Comparative Example 1, Example 3, Example 4, Example 11 and Example 25. The frequency at the maximum value can be adjusted by the dielectric constant and the thickness of the glass. Agreement between the measured value and the calculated value was confirmed.

In Tables, “-” means that measurement was not conducted, and values obtained by calculation from the composition were represented in italics

TABLE 1 Comp. Ex. 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Embodiment 5 3 4 5 4 1 2 1 3 SiO₂ (mol %) 69.76 66.00 66.00 67.03 70.03 66.03 66.11 71.40 66.00 66.00 Al₂O₃ (mol %) 0.88 2.95 2.95 1.90 0.50 4.00 3.00 2.48 2.95 2.95 B₂O₃ (mol %) 0 0 0 0 0 0.50 0 0 0 0 MgO (mol %) 7.08 0.50 0.50 1.50 5.00 3.40 11.00 8.10 12.48 0 CaO (mol %) 9.09 11.98 11.98 12.00 11.90 10.00 1.57 10.00 0 12.48 SrO (mol %) 0 0 0 1.00 0 0 0 0 0 0 BaO (mol %) 0 0 0 1.00 0 0 0 0 0 0 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0 0 0 0 0 0 1.95 0 0 0 Li₂O (mol %) 0 4.00 0 1.50 3.50 3.00 0 0 0 0 Na₂O (mol %) 12.55 11.00 15.00 8.00 5.50 6.00 8.30 6.05 15.00 15.00 K₂O (mol %) 0.57 3.50 3.50 6.00 3.50 7.00 8.00 1.90 3.50 3.50 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 16.17 12.48 12.48 15.50 16.90 13.40 12.57 18.10 12.48 12.48 R₂O (mol %) 13.12 18.50 18.50 15.50 12.50 16.00 16.30 7.95 18.50 18.50 7Al₂O₃ + 3MgO (mol %) 27.4 22.2 22.2 17.8 18.5 38.2 54.0 41.7 58.1 20.7 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 27.4 6.2 22.2 11.8 4.5 26.2 54.0 41.7 58.1 20.7 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 99.5 98.1 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 16.2 12.5 12.5 13.5 16.9 13.4 12.6 18.1 12.5 12.5 R₂O × MgO (mol %)² 92.9 9.3 9.3 23.3 62.5 54.4 179.3 64.4 230.9 0.0 Na₂O/R₂O 0.96 0.59 0.81 0.52 0.44 0.38 0.51 0.76 0.81 0.81 K₂O/R₂O 0.04 0.19 0.19 0.39 0.28 0.44 0.49 0.24 0.19 0.19 R₂O + B₂O₃ (mol %) 13.1 18.5 18.5 15.5 12.5 16.5 16.3 8.0 18.5 18.5 SiO₂ + Al₂O₃ (mol %) 70.6 69.0 69.0 68.9 70.5 70.0 69.1 73.9 69.0 69.0 FeO (mol %) — — — — — — — — — — Fe-Redox (%) — — — — — — — — — — Exponential approximation formula of relation 0.8619 0.8422 0.8434 0.843 0.8567 0.8451 0.843 0.843 0.8452 0.8426 between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation −0.015 −0.007 −0.007 −0.01 −0.008 −0.009 −0.009 −0.009 −0.008 −0.009 between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 19% 42% 42% 31% 38% 34% 34% 34% 38% 34% at 100 GHz d 2.48 2.54 2.54 2.60 2.49 2.56 2.52 2.48 2.47 2.55 α (×10⁻⁷/° C.) 93 108 109 103 88 97 95 73 105 109 E (GPa) 78 78 74 74 80 74 74 80 75 74 T_(g) (° C.) 528 487 525 515 513 537 569 628 536 548 T₂ (° C.) 1450 1432 1466 1474 1460 1523 1551 1552 1499 1464 T₄ (° C.) 1019 969 991 1045 1063 1074 1102 1176 991 991 T_(L) (° C.) — — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — — Water resistance (mg) 0.63 0.17 0.05 0.27 0.40 0.17 0.25 0.30 0.47 0.04 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0173 0.0376 0.0377 0.0279 0.0346 0.0282 0.0306 0.0306 0.0342 0.0306 Radio transmittance/t (thickness: 3.85 mm) 5.0 10.9 10.9 8.1 10.0 8.1 8.8 8.8 9.9 8.8 β-OH (mm⁻¹) — — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — — Maximum radio transmitted amount −4.1 — — −2.0 −2.6 — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount 89.2 — — 83.0 84.9 — — — — — of laminated glass (GHz) Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Embodiment 3 3 3 5 6 3 4 1 1 SiO₂ (mol %) 66.00 66.00 66.00 66.00 66.00 72.38 70.93 65.83 62.00 Al₂O₃ (mol %) 2.95 2.95 2.95 2.95 2.95 1.51 2.00 6.08 6.93 B₂O₃ (mol %) 0 0 0 0 0 0 0 0 0 MgO (mol %) 0 0 0.50 0.50 0.50 0.10 11.00 0.0 0.50 CaO (mol %) 0 0 11.98 11.98 11.98 11.57 2.00 10.86 12.00 SrO (mol %) 12.48 0 0 0 0 0 0 0 0 BaO (mol %) 0 12.48 0 0 0 0 0 0 0 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0 0 0 0 0 0 0 0 0 Li₂O (mol %) 0 0 0 6.17 18.5 0 5 0 0 Na₂O (mol %) 15.00 15.00 11.00 6.17 0 10.05 5.00 13.11 15.00 K₂O (mol %) 3.50 3.50 7.50 6.17 0.0 4.32 4.00 4.05 3.50 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 12.48 12.48 12.48 12.48 12.48 11.67 13.00 10.86 12.50 R₂O (mol %) 18.50 18.50 18.50 18.51 18.50 14.37 14.00 17.16 18.50 7Al₂O₃ + 3MgO (mol %) 20.7 20.7 22.2 22.2 22.2 10.9 47.0 42.6 50.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 20.7 20.7 22.2 −2.5 −51.9 10.9 27.0 42.6 50.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 0.0 0.0 12.5 12.5 12.5 11.7 13.0 10.9 12.5 R₂O × MgO (mol %)² 0.0 0.0 9.3 9.3 9.3 1.4 154.0 0.0 9.3 Na₂O/R₂O 0.81 0.81 0.59 0.33 0.00 0.70 0.36 0.76 0.81 K₂O/R₂O 0.19 0.19 0.41 0.33 0.00 0.30 0.29 0.24 0.19 R₂O + B₂O₃ (mol %) 18.5 18.5 18.5 18.5 18.5 14.4 14.0 17.2 18.5 SiO₂ + Al₂O₃ (mol %) 69.0 69.0 69.0 69.0 69.0 73.9 72.9 71.9 68.9 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation 0.8426 0.8437 0.8425 0.8435 0.8468 0.8462 0.8625 0.8433 0.8428 between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation −0.009 −0.009 −0.008 −0.006 −0.008 −0.007 −0.008 −0.01 −0.012 between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 34% 34% 38% 46% 38% 42% 39% 31% 25% at 100 GHz d 2.74 2.93 2.54 2.52 2.49 2.49 2.47 2.52 2.55 α (×10⁻⁷/° C.) 116 120 112 103 83 95 80 101 113 E (GPa) 72 68 70 77 91 74 80 75 75 T_(g) (° C.) 510 484 537 498 494 547 550 570 557 T₂ (° C.) 1464 1464 1514 1315 1267 1444 1548 1554 1489 T₄ (° C.) 913 991 1048 931 839 1031 1079 1091 1048 T_(L) (° C.) — — — 1020 — 1000 — — — T₄ − T_(L) (° C.) — — — −89 — 31 — — — Water resistance (mg) 0.04 0.04 0.17 0.24 0.20 0.29 0.32 — — Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0306 0.0306 0.0333 0.0414 0.0342 0.0378 0.0342 0.0279 0.0225 Radio transmittance/t (thickness: 3.85 mm) 8.8 8.8 9.6 11.9 9.9 10.9 9.9 8.1 6.5 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — −2.4 — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — 79.7 — — — — — — — of laminated glass (GHz) Comp. Ex. 19 Ex. 20 Ex. 21 Ex. 22 Ex. 23 Ex. 24 Ex. 2 Ex. 25 Ex. 26 Embodiment 4 4 6 3 6 1 1 1 SiO₂ (mol %) 68.96 69.96 66.00 66.00 66.00 62.00 68.28 61.96 61.96 Al₂O₃ (mol %) 8.99 7.50 2.96 2.96 2.96 6.96 0.92 5.00 5.00 B₂O₃ (mol %) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 6.00 7.00 0.50 0.50 0.50 0.50 6.36 2.50 3.50 CaO (mol %) 0 0.20 11.98 11.98 11.98 11.98 9.20 11.99 10.99 SrO (mol %) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.05 0.05 ZrO₂ (mol %) 1.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 9.49 8.00 9.25 0.00 9.25 0.00 0.00 0.00 0.00 Na₂O (mol %) 4.50 5.30 9.25 9.25 0.00 9.25 12.61 9.24 9.24 K₂O (mol %) 1.00 1.00 0.00 9.25 9.25 9.25 0.39 9.24 9.24 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 2.20 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 6.00 7.20 12.48 12.48 12.48 12.48 15.56 14.49 14.49 R₂O (mol %) 14.99 14.30 18.50 18.50 18.50 18.50 13.00 18.48 18.48 7Al₂O₃ + 3MgO (mol %) 80.9 73.5 22.2 22.2 22.2 50.2 25.5 42.5 45.5 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 43.0 41.5 −14.8 22.2 −14.8 50.2 25.5 42.5 45.5 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 99.0 99.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 6.0 7.2 12.5 12.5 12.5 12.5 15.6 14.5 14.5 R₂O × MgO (mol %)² 89.9 100.1 9.3 9.3 9.3 9.3 82.7 46.2 64.7 Na₂O/R₂O 0.30 0.37 0.50 0.50 0.00 0.50 0.97 0.50 0.50 K₂O/R₂O 0.07 0.07 0.00 0.50 0.50 0.50 0.03 0.50 0.50 R₂O + B₂O₃ (mol %) 15.0 14.3 18.5 18.5 18.5 18.5 13.0 18.5 18.5 SiO₂ + Al₂O₃ (mol %) 78.0 77.5 69.0 69.0 69.0 69.0 69.2 67.0 67.0 FeO (mol %) — — — — — — 0.660 — — Fe-Redox (%) — — — — — — 30 — — Exponential approximation formula of relation 0.8599 0.8807 — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation −0.011 −0.010 — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 29% 32% 35% 39% 32% 36% 19% 38% 37% at 100 GHz d 2.44 2.44 2.52 2.52 2.49 2.54 2.52 2.53 2.53 α (×10⁻⁷/° C.) 70 72 96 113 100 111 93 112 111 E (GPa) 84 83 86 67 75 69 78 69 69 T_(g) (° C.) 552 548 482 542 554 573 528 542 546 T₂ (° C.) 1664 1640 1344 1534 1456 1447 1450 1393 1407 T₄ (° C.) 1163 1159 889 1073 1022 1044 1019 1011 1018 T_(L) (° C.) — — — — — 1100 — 1040 — T₄ − T_(L) (° C.) — — — — — −56 — −29 — Water resistance (mg) — — 0.21 0.21 0.20 0.07 0.61 0.07 0.05 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ X ◯ ◯ Visible light transmittance T_(VA) — — — — — — 27.4 — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ X ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — 11.6 — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — 1.3 — — A × radio transmittance (area: 0.0009 m²) 0.0261 0.0288 0.0313 0.0354 0.0287 0.0321 0.0171 0.0340 0.0335 Radio transmittance/t (thickness: 3.85 mm) 7.5 8.3 9.0 10.2 8.3 9.3 4.9 9.8 9.7 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — 0.001 — — Transmittance at wavelength 1550 nm (%) — — — — — — 0.04 — — Maximum radio transmitted amount — — — — — — — −2.6 — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — 78.4 — of laminated glass (GHz) Ex. 27 Ex. 28 Ex. 29 Ex. 30 Ex. 31 Ex. 32 Ex. 33 Ex. 34 Ex. 35 Embodiment 1 1 1 1 1 1 1 1 1 SiO₂ (mol %) 61.96 62.75 68.75 62.00 61.94 62.00 60.50 61.90 61.90 Al₂O₃ (mol %) 5.00 4.50 4.50 6.96 5.00 6.96 6.96 6.99 6.99 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 1.50 0.00 0.00 MgO (mol %) 3.50 3.70 3.70 0.50 8.50 0.50 0.50 0.50 0.50 CaO (mol %) 13.49 10.98 10.98 11.98 8.50 11.98 11.98 11.98 11.98 SrO (mol %) 0.00 0.00 0.00 1.50 0.00 1.50 1.50 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 3.00 3.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.04 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 7.99 9.00 6.00 8.50 8.00 7.00 7.00 9.24 9.24 K₂O (mol %) 7.99 9.00 6.00 8.50 8.00 7.00 7.00 9.23 9.23 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.12 0.12 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 16.99 14.68 14.68 13.98 17.00 16.98 16.98 12.48 12.48 R₂O (mol %) 15.98 18.00 12.00 17.00 16.00 14.00 14.00 18.47 18.47 7Al₂O₃ + 3MgO (mol %) 45.5 42.6 42.6 50.2 60.5 50.2 50.2 50.4 50.4 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 45.5 42.6 42.6 50.2 60.5 50.2 50.2 50.4 50.4 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 98.5 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 17.0 14.7 14.7 12.5 17.0 12.5 12.5 12.5 12.5 R₂O × MgO (mol %)² 55.9 66.6 44.4 8.5 136.0 7.0 7.0 9.2 9.2 Na₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 K₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 R₂O + B₂O₃ (mol %) 16.0 18.0 12.0 17.0 16.0 14.0 15.5 18.5 18.5 SiO₂ + Al₂O₃ (mol %) 67.0 67.3 73.3 69.0 66.9 69.0 67.5 68.9 68.9 FeO (mol %) — — — — — — — 0.0382 0.0691 Fe-Redox (%) — — — — — — — 31 56 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 35% 37% 31% 34% 32% 33% 37% 36% 36% at 100 GHz d 2.55 2.53 2.50 2.58 2.53 2.68 2.68 2.54 2.54 α (×10⁻⁷/° C.) 105 110 88 106 101 101 99 111 111 E (GPa) 73 70 75 71 73 73 72 69 69 T_(g) (° C.) 578 547 612 579 562 588 574 573 573 T₂ (° C.) 1403 1405 1529 1438 1441 1433 1405 1447 1447 T₄ (° C.) 1026 1015 1114 1051 1060 1054 1038 1044 1044 T_(L) (° C.) — — — — 1060 — — 1100 1100 T₄ − T_(L) (° C.) — — — — 0 — — −56 −56 Water resistance (mg) 0.07 0.09 0.18 0.11 0.02 0.17 0.15 0.07 0.07 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — 84.7 80.3 measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — 67.3 55.7 Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — 41.5 45.8 A × radio transmittance (area: 0.0009 m²) 0.0311 0.0330 0.0275 0.0308 0.0292 0.0299 0.0333 0.0320 0.0320 Radio transmittance/t (thickness: 3.85 mm) 9.0 9.5 7.9 8.9 8.4 8.6 9.6 9.2 9.2 β-OH (mm⁻¹) — — — — — — — 0.18 0.25 Transmittance at wavelength 905 nm (%) — — — — — — — 49.4 29.2 Transmittance at wavelength 1550 nm (%) — — — — — — — 60.5 41.5 Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 36 Ex. 37 Ex. 38 Ex. 39 Ex. 40 Ex. 41 Ex. 42 Ex. 43 Ex. 44 Embodiment 1 1 1 1 1 1 1 2 2 SiO₂ (mol %) 68.75 68.75 64.46 62.46 62.46 63.26 64.06 69.60 71.10 Al₂O₃ (mol %) 6.00 6.00 7.00 9.00 6.00 7.00 7.00 2.48 2.78 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.80 0.00 MgO (mol %) 2.20 2.20 1.50 0.80 0.50 3.50 1.00 8.10 7.00 CaO (mol %) 10.98 10.98 6.98 6.68 6.98 2.00 10.48 10.00 11.10 SrO (mol %) 0.00 0.00 1.00 2.00 0.00 7.98 2.00 0.00 0.00 BaO (mol %) 0.00 0.00 7.00 5.00 9.00 6.40 6.40 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.04 0.04 0.04 0.04 0.04 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 2.00 0.00 1.00 1.80 1.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 8.20 3.20 5.00 7.00 7.00 4.00 4.00 6.05 4.28 K₂O (mol %) 3.80 8.80 5.00 7.00 7.00 4.00 4.00 1.90 3.68 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 13.18 13.18 16.48 14.48 16.48 19.88 19.88 18.10 18.10 R₂O (mol %) 12.00 12.00 10.00 14.00 14.00 8.00 8.00 7.95 7.96 7Al₂O₃ + 3MgO (mol %) 48.6 48.6 53.5 65.4 43.5 59.5 52.0 41.7 40.5 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 48.6 48.6 53.5 65.4 43.5 59.5 52.0 41.7 40.5 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 98.0 100.0 99.0 98.2 99.0 98.2 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 13.2 13.2 8.5 7.5 7.5 5.5 11.5 18.1 18.1 R₂O × MgO (mol %)² 26.4 26.4 15.0 11.2 7.0 28.0 8.0 64.4 55.7 Na₂O/R₂O 0.68 0.27 0.50 0.50 0.50 0.50 0.50 0.76 0.54 K₂O/R₂O 0.32 0.73 0.50 0.50 0.50 0.50 0.50 0.24 0.46 R₂O + B₂O₃ (mol %) 12.0 12.0 10.0 14.0 14.0 8.0 8.0 9.8 8.0 SiO₂ + Al₂O₃ (mol %) 74.8 74.8 71.5 71.5 68.5 70.3 71.1 72.1 73.9 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 27% 30% 30% 31% 34% 32% 32% 33% 32% at 100 GHz d 2.50 2.49 2.68 2.72 2.77 2.79 2.76 2.50 2.49 α (×10⁻⁷/° C.) 84 88 83 98 102 81 81 69 73 E (GPa) 76 71 77 72 72 79 79 78 79 T_(g) (° C.) 616 647 637 593 569 653 644 606 635 T₂ (° C.) 1555 1567 1571 1501 1470 1553 1519 1514 1563 T₄ (° C.) 1130 1164 1144 1109 1041 1157 1125 1096 1137 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.14 0.22 0.19 0.13 0.18 0.04 0.25 0.28 0.21 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0243 0.0271 0.0269 0.0282 0.0306 0.0284 0.0291 0.0299 0.0286 Radio transmittance/t (thickness: 3.85 mm) 7.0 7.8 7.8 8.1 8.8 8.2 8.4 8.6 8.3 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 45 Ex. 46 Ex. 47 Ex. 48 Ex. 49 Ex. 50 Ex. 51 Ex. 52 Ex. 53 Embodiment 2 2 2 2 2 2 2 2 2 SiO₂ (mol %) 71.10 71.40 71.40 71.40 71.40 71.40 71.10 68.21 66.71 Al₂O₃ (mol %) 2.78 2.48 2.48 2.48 2.48 2.48 2.78 2.38 2.38 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.50 MgO (mol %) 4.00 8.10 8.10 8.10 8.10 7.05 3.05 2.89 2.89 CaO (mol %) 14.10 3.50 3.50 3.70 3.70 10.00 14.00 13.30 13.30 SrO (mol %) 0.00 6.50 6.50 3.50 3.50 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 2.80 2.80 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 4.28 6.05 4.28 6.05 4.28 4.50 4.50 9.50 9.50 K₂O (mol %) 3.68 1.90 3.68 1.90 3.68 4.50 4.50 3.65 3.65 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 18.10 18.10 18.10 18.10 18.10 17.05 17.05 16.19 16.19 R₂O (mol %) 7.96 7.95 7.96 7.95 7.96 9.00 9.00 13.15 13.15 7Al₂O₃ + 3MgO (mol %) 31.5 41.7 41.7 41.7 41.7 38.5 28.6 25.3 25.3 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 31.5 41.7 41.7 41.7 41.7 38.5 28.6 25.3 25.3 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 98.5 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 18.1 11.6 11.6 11.8 11.8 17.1 17.1 16.2 16.2 R₂O × MgO (mol %)² 31.8 64.4 64.5 64.4 64.5 63.5 27.5 38.0 38.0 Na₂O/R₂O 0.54 0.76 0.54 0.76 0.54 0.50 0.50 0.72 0.72 K₂O/R₂O 0.46 0.24 0.46 0.24 0.46 0.50 0.50 0.28 0.28 R₂O + B₂O₃ (mol %) 8.0 8.0 8.0 8.0 8.0 9.0 9.0 13.2 14.7 SiO₂ + Al₂O₃ (mol %) 73.9 73.9 73.9 73.9 73.9 73.9 73.9 70.6 69.1 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 31% 32% 35% 32% 35% 32% 31% 30% 33% at 100 GHz d 2.50 2.62 2.61 2.66 2.65 2.48 2.50 2.53 2.54 α (×10⁻⁷/° C.) 75 73 75 74 76 77 79 94 94 E (GPa) 79 79 78 78 78 78 77 76 75 T_(g) (° C.) 640 611 616 595 602 623 632 573 560 T₂ (° C.) 1546 1543 1554 1549 1559 1558 1536 1435 1408 T₄ (° C.) 1134 1104 1112 1093 1101 1128 1126 1028 1004 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.25 0.30 0.23 0.30 0.23 0.25 0.27 0.28 0.27 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0282 0.0286 0.0313 0.0291 0.0316 0.0286 0.0280 0.0270 0.0301 Radio transmittance/t (thickness: 3.85 mm) 8.1 8.3 9.0 8.4 9.1 8.3 8.1 7.8 8.7 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 54 Ex. 55 Ex. 56 Ex. 57 Ex. 58 Ex. 59 Ex. 60 Ex. 61 Ex. 62 Embodiment 2 2 2 2 2 2 2 2 2 SiO₂ (mol %) 68.21 68.21 68.21 68.21 68.21 68.21 70.45 70.45 70.45 Al₂O₃ (mol %) 2.38 4.88 4.88 4.88 4.88 2.38 4.00 4.00 2.90 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 2.89 0.39 0.39 0.39 0.39 2.89 0.00 0.00 0.00 CaO (mol %) 13.30 13.30 10.30 10.80 15.45 13.30 17.49 15.49 15.49 SrO (mol %) 0.00 0.00 3.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 2.50 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 6.57 6.57 6.57 6.57 5.50 4.07 4.00 5.00 5.55 K₂O (mol %) 6.57 6.57 6.57 6.57 5.50 9.07 4.00 5.00 5.55 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 16.19 13.69 13.69 13.69 15.84 16.19 17.49 15.49 15.49 R₂O (mol %) 13.14 13.14 13.14 13.14 11.00 13.14 8.00 10.00 11.10 7Al₂O₃ + 3MgO (mol %) 25.3 35.3 35.3 35.3 35.3 25.3 28.0 28.0 20.3 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 25.3 35.3 35.3 35.3 35.3 25.3 28.0 28.0 20.3 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 16.2 13.7 10.7 11.2 15.8 16.2 17.5 15.5 15.5 R₂O × MgO (mol %)² 38.0 5.1 5.1 5.1 4.3 38.0 0.0 0.0 0.0 Na₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.31 0.50 0.50 0.50 K₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.69 0.50 0.50 0.50 R₂O + B₂O₃ (mol %) 13.1 13.1 13.1 13.1 11.0 13.1 8.0 10.0 11.1 SiO₂ + Al₂O₃ (mol %) 70.6 73.1 73.1 73.1 73.1 70.6 74.5 74.5 73.4 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 33% 31% 32% 32% 30% 32% 31% 30% 31% at 100 GHz d 2.52 2.51 2.58 2.59 2.53 2.52 2.52 2.51 2.52 α (×10⁻⁷/° C.) 96 93 94 94 87 96 77 83 88 E (GPa) 74 73 73 72 76 71 78 76 75 T_(g) (° C.) 583 607 595 582 634 600 650 636 615 T₂ (° C.) 1441 1497 1492 1497 1503 1445 1547 1526 1488 T₄ (° C.) 1045 1093 1086 1077 1108 1061 1147 1126 1091 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.27 0.26 0.26 0.26 0.28 0.24 0.32 0.31 0.29 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0294 0.0279 0.0286 0.0289 0.0274 0.0284 0.0276 0.0273 0.0279 Radio transmittance/t (thickness: 3.85 mm) 8.5 8.0 8.2 8.4 7.9 8.2 8.0 7.9 8.0 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 63 Ex. 64 Ex. 65 Ex. 66 Ex. 67 Ex. 68 Ex. 69 Ex. 70 Ex. 71 Embodiment 2 2 2 2 2 2 2 2 2 SiO₂ (mol %) 70.45 70.45 70.45 70.45 70.45 70.45 70.43 70.43 70.45 Al₂O₃ (mol %) 4.00 4.00 4.00 4.00 4.00 4.00 5.60 5.00 4.00 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.50 0.00 CaO (mol %) 17.49 17.49 10.99 10.99 14.49 15.89 8.90 7.00 17.49 SrO (mol %) 0.00 0.00 6.50 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 6.50 3.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 4.20 5.00 4.00 4.00 4.00 4.80 7.50 8.00 5.89 K₂O (mol %) 3.80 3.00 4.00 4.00 4.00 4.80 7.50 8.00 2.10 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 17.49 17.49 17.49 17.49 17.49 15.89 8.90 8.50 17.49 R₂O (mol %) 8.00 8.00 8.00 8.00 8.00 9.60 15.00 16.00 7.99 7Al₂O₃ + 3MgO (mol %) 28.0 28.0 28.0 28.0 28.0 28.0 39.2 39.5 28.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 28.0 28.0 28.0 28.0 28.0 28.0 39.2 39.5 28.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 17.5 17.5 11.0 11.0 14.5 15.9 8.9 8.5 17.5 R₂O × MgO (mol %)² 0.0 0.0 0.0 0.0 0.0 0.0 0.0 24.0 0.0 Na₂O/R₂O 0.53 0.63 0.50 0.50 0.50 0.50 0.50 0.50 0.74 K₂O/R₂O 0.48 0.38 0.50 0.50 0.50 0.50 0.50 0.50 0.26 R₂O + B₂O₃ (mol %) 8.0 8.0 8.0 8.0 8.0 9.6 15.0 16.0 8.0 SiO₂ + Al₂O₃ (mol %) 74.5 74.5 74.5 74.5 74.5 74.5 76.0 75.4 74.5 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 31% 30% 33% 34% 32% 30% 31% 32% 29% at 100 GHz d 2.52 2.52 2.65 2.73 2.62 2.51 2.48 2.47 2.53 α (×10⁻⁷/° C.) 76 75 79 81 79 81 94 98 74 E (GPa) 78 79 77 75 77 77 70 69 79 T_(g) (° C.) 661 657 634 608 630 642 587 569 653 T₂ (° C.) 1534 1530 1523 1535 1535 1528 1552 1545 1526 T₄ (° C.) 1142 1135 1124 1097 1122 1130 1121 1107 1128 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.32 0.31 0.32 0.32 0.32 0.32 0.27 0.22 0.30 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0275 0.0269 0.0297 0.0305 0.0289 0.0273 0.0278 0.0288 0.0255 Radio transmittance/t (thickness: 3.85 mm) 7.9 7.8 8.6 8.8 8.3 7.9 8.0 8.3 7.4 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 72 Ex. 73 Ex. 74 Ex. 75 Ex. 76 Ex. 77 Ex. 78 Ex. 79 Ex. 80 Embodiment 2 3 3 3 3 3 3 3 3 SiO₂ (mol %) 70.45 72.38 72.38 72.38 72.27 72.27 72.38 71.90 71.90 Al₂O₃ (mol %) 4.00 1.51 1.51 1.51 1.51 1.51 1.51 1.70 1.70 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 0.00 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 CaO (mol %) 15.99 11.56 11.56 11.56 11.54 11.54 11.56 11.52 11.52 SrO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 ZrO₂ (mol %) 1.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 5.89 10.56 8.04 7.19 7.18 7.18 7.19 7.16 7.16 K₂O (mol %) 2.10 3.81 6.33 7.19 7.18 7.18 7.19 7.16 7.16 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.19 0.19 0.04 0.11 0.11 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.22 0.22 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.09 0.09 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 15.99 11.66 11.66 11.66 11.64 11.64 11.66 11.62 11.62 R₂O (mol %) 7.99 14.37 14.37 14.38 14.36 14.36 14.38 14.32 14.32 7Al₂O₃ + 3MgO (mol %) 28.0 10.9 10.9 10.9 10.9 10.9 10.9 12.2 12.2 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 28.0 10.9 10.9 10.9 10.9 10.9 10.9 12.2 12.2 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 98.5 100.0 100.0 100.0 100.0 100.0 100.0 99.7 99.7 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 16.0 11.7 11.7 11.7 11.6 11.6 11.7 11.6 11.6 R₂O × MgO (mol %)² 0.0 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 Na₂O/R₂O 0.74 0.73 0.56 0.50 0.50 0.50 0.50 0.50 0.50 K₂O/R₂O 0.26 0.27 0.44 0.50 0.50 0.50 0.50 0.50 0.50 R₂O + B₂O₃ (mol %) 8.0 14.4 14.4 14.4 14.4 14.4 14.4 14.3 14.3 SiO₂ + Al₂O₃ (mol %) 74.5 73.9 73.9 73.9 73.8 73.8 73.9 73.6 73.6 FeO (mol %) — — — 0.0042 0.0512 0.0872 0.0123 0.0761 0.0607 Fe-Redox (%) — — — 21 27 46 31 69 55 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 27% 30% 33% 33% 33% 33% 33% 33% 33% at 100 GHz d 2.56 2.49 2.49 2.49 2.49 2.49 2.49 2.49 2.49 α (×10⁻⁷/° C.) 70 96 95 97 97 97 97 98 98 E (GPa) 80 73 71 70 71 71 70 71 71 T_(g) (° C.) 669 545 556 560 560 560 560 561 561 T₂ (° C.) 1536 1448 1466 1464 1464 1464 1464 1469 1469 T₄ (° C.) 1147 1037 1052 1050 1050 1050 1050 1055 1055 T_(L) (° C.) — — — 990 990 990 990 — — T₄ − T_(L) (° C.) — — — 60 60 60 60 — — Water resistance (mg) 0.30 0.28 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — 91.6 83.7 79.6 89.8 81.3 82.8 measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — 91.4 62.7 52.1 82.6 55.4 59.7 Ultraviolet transmittance T_(uv) measured value (%) — — — 85.2 41.5 44.7 69.4 32.5 31.8 A × radio transmittance (area: 0.0009 m²) 0.0239 0.0272 0.0298 0.0301 0.0301 0.0301 0.0301 0.0299 0.0299 Radio transmittance/t (thickness: 3.85 mm) 6.9 7.9 8.6 8.7 8.7 8.7 8.7 8.6 8.6 β-OH (mm⁻¹) — — — 0.17 0.19 0.15 0.3 0.27 0.18 Transmittance at wavelength 905 nm (%) — — — 91.8 42.1 24.1 76.0 27.7 35.0 Transmittance at wavelength 1550 nm (%) — — — 92.0 49.3 31.0 78.8 40.4 48.0 Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 81 Ex. 82 Ex. 83 Ex. 84 Ex. 85 Ex. 86 Ex. 87 Ex. 88 Ex. 89 Embodiment 3 3 3 3 3 3 3 3 3 SiO₂ (mol %) 72.33 72.33 72.24 71.35 71.75 71.75 72.25 69.58 70.88 Al₂O₃ (mol %) 1.51 1.51 1.51 2.20 2.00 2.20 2.50 2.51 3.01 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0 0 0 1.80 0.00 MgO (mol %) 0.10 0.10 0.10 2.00 0.50 0.80 0.30 0.10 0.10 CaO (mol %) 11.55 11.55 11.54 10.00 11.85 10.80 8.90 11.56 9.56 SrO (mol %) 0.00 0.00 0.00 0.00 0 0 0 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0 0 0 0.00 0.00 TiO₂ (mol %) 0.04 0.04 0.04 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0 0 0 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0 0 0 0.00 0.00 Na₂O (mol %) 7.18 7.18 7.17 7.19 6.80 7.00 7.70 6.69 8.19 K₂O (mol %) 7.18 7.18 7.17 7.19 6.80 7.00 7.70 6.69 8.19 Fe₂O₃ (mol %) 0.11 0.11 0.04 0.02 0.25 0.40 0.60 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.18 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 0.00 RO (mol %) 11.65 11.65 11.64 12.00 12.35 11.60 9.20 11.66 9.66 R₂O (mol %) 14.36 14.36 14.34 14.38 13.60 14.00 15.40 13.38 16.38 7Al₂O₃ + 3MgO (mol %) 10.9 10.9 10.9 21.4 15.5 17.8 18.4 17.9 21.4 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 10.9 10.9 10.9 21.4 15.5 17.8 18.4 17.9 21.4 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 99.8 100.0 100.0 100.0 100.0 97.2 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 11.7 11.7 11.6 12.0 12.4 11.6 9.2 11.7 9.7 R₂O × MgO (mol %)² 1.4 1.4 1.4 28.8 6.8 11.2 4.6 1.3 1.6 Na₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 K₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 R₂O + B₂O₃ (mol %) 14.4 14.4 14.3 14.4 13.6 14.0 15.4 15.2 16.4 SiO₂ + Al₂O₃ (mol %) 73.8 73.8 73.8 73.6 73.8 74.0 74.8 72.1 73.9 FeO (mol %) 0.0620 0.0476 0.0008 — 0.0963 0.0900 0.1500 — — Fe-Redox (%) 56 43 2 — 38.5 22.5 25 — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 33% 33% 33% 33% 33% 33% 34% 36% 34% at 100 GHz d 2.49 2.49 2.49 2.48 2.49 2.49 2.47 2.51 2.48 α (×10⁻⁷/° C.) 97 97 97 97 95 96 100 93 103 E (GPa) 71 71 71 71 72 72 70 69 71 T_(g) (° C.) 560 560 560 563 572 568 553 562 547 T₂ (° C.) 1464 1464 1464 1490 1483 1490 1498 1449 1480 T₄ (° C.) 1050 1050 1050 1068 1068 1070 1067 1039 1056 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.30 0.30 0.30 0.31 0.30 0.30 0.30 0.27 0.29 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) 82.8 84.6 91.2 — 77.5 76.5 68.6 — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) 59.8 64.8 88.9 — 49.5 49.1 37.4 — — Ultraviolet transmittance T_(uv) measured value (%) 58.8 55.2 32.7 — 38.5 25.5 18.0 — — A × radio transmittance (area: 0.0009 m²) 0.0301 0.0301 0.0301 0.0297 0.0293 0.0294 0.0302 0.0328 0.0310 Radio transmittance/t (thickness: 3.85 mm) 8.7 8.7 8.7 8.6 8.4 8.5 8.7 9.5 8.9 β-OH (mm⁻¹) 0.25 0.35 0.12 — — — — — — Transmittance at wavelength 905 nm (%) 33.5 42.0 90.9 — 19.8 22.3 8.7 — — Transmittance at wavelength 1550 nm (%) 46.4 54.4 91.4 — 32.8 35.3 18.6 — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 90 Ex. 91 Ex. 92 Ex. 93 Ex. 94 Ex. 95 Ex. 96 Ex. 97 Ex. 98 Embodiment 3 3 3 3 3 3 3 3 3 SiO₂ (mol %) 70.50 70.88 70.68 72.38 72.38 72.38 71.58 72.38 72.38 Al₂O₃ (mol %) 1.83 3.01 3.31 1.51 2.01 2.01 1.31 1.51 1.31 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 MgO (mol %) 0.10 0.10 0.00 2.60 2.60 0.10 0.10 0.10 3.00 CaO (mol %) 10.00 9.56 2.56 9.06 12.56 15.06 16.56 17.56 10.86 SrO (mol %) 0.00 2.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 8.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 8.75 7.19 7.19 7.19 5.19 5.19 5.19 4.19 4.19 K₂O (mol %) 8.75 7.19 7.19 7.19 5.19 5.19 5.19 4.19 4.19 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.00 RO (mol %) 10.10 11.66 11.56 11.66 15.16 15.16 16.66 17.66 13.86 R₂O (mol %) 17.50 14.38 14.38 14.38 10.38 10.38 10.38 8.38 8.38 7Al₂O₃ + 3MgO (mol %) 13.1 21.4 23.2 18.4 21.9 14.4 9.5 10.9 18.2 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 13.1 21.4 23.2 18.4 21.9 14.4 9.5 10.9 18.2 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 96.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 10.1 9.7 2.6 11.7 15.2 15.2 16.7 17.7 13.9 R₂O × MgO (mol %)² 1.8 1.4 0.0 37.4 27.0 1.0 1.0 0.8 25.1 Na₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 K₂O/R₂O 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 R₂O + B₂O₃ (mol %) 17.5 14.4 14.4 14.4 10.4 10.4 10.4 8.4 9.4 SiO₂ + Al₂O₃ (mol %) 72.3 73.9 74.0 73.9 74.4 74.4 72.9 73.9 73.7 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 37% 33% 38% 33% 31% 31% 31% 31% 34% at 100 GHz d 2.49 2.54 2.73 2.47 2.49 2.50 2.52 2.51 2.49 α (×10⁻⁷/° C.) 109 98 103 97 83 85 87 79 77 E (GPa) 71 71 67 71 75 75 76 77 76 T_(g) (° C.) 523 564 528 556 608 613 610 636 609 T₂ (° C.) 1430 1485 1491 1495 1533 1510 1468 1504 1524 T₄ (° C.) 1015 1066 1015 1067 1113 1107 1078 1115 1095 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.29 0.29 0.28 0.36 0.31 0.30 0.28 0.29 0.31 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0336 0.0299 0.0341 0.0301 0.0281 0.0278 0.0281 0.0278 0.0308 Radio transmittance/t (thickness: 3.85 mm) 9.7 8.6 9.8 8.7 8.1 8.0 8.1 8.0 8.9 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 99 Ex. 100 Ex. 101 Ex. 102 Ex. 103 Ex. 104 Ex. 105 Ex. 106 Ex. 107 Embodiment 3 3 3 3 3 3 3 3 3 SiO₂ (mol %) 72.36 71.98 72.38 71.34 71.34 71.34 72.40 72.40 72.40 Al₂O₃ (mol %) 1.31 1.51 1.51 2.10 2.10 2.10 1.51 1.51 1.51 B₂O₃ (mol %) 1.90 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 4.50 1.50 0.10 1.00 1.00 1.00 0.10 0.10 0.10 CaO (mol %) 11.48 13.56 11.56 10.99 10.99 10.99 11.56 11.56 11.56 SrO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 2.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.04 0.04 ZrO₂ (mol %) 0.00 0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 3.19 5.19 2.31 10.50 7.25 4.50 10.06 10.06 10.06 K₂O (mol %) 3.19 5.19 12.06 4.00 7.25 9.99 4.32 4.32 4.32 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.004 0.004 0.004 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0020 0.0041 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 17.98 15.06 11.66 11.99 11.99 11.99 11.66 11.66 11.66 R₂O (mol %) 6.38 10.38 14.37 14.50 14.50 14.49 14.38 14.38 14.38 7Al₂O₃ + 3MgO (mol %) 22.7 15.1 10.9 17.7 17.7 17.7 10.9 10.9 10.9 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 22.7 15.1 10.9 17.7 17.7 17.7 10.9 10.9 10.9 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 98.1 99.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 16.0 15.1 11.7 12.0 12.0 12.0 11.7 11.7 11.7 R₂O × MgO (mol %)² 28.7 15.6 1.4 14.5 14.5 14.5 1.4 1.4 1.4 Na₂O/R₂O 0.50 0.50 0.16 0.72 0.50 0.31 0.70 0.70 0.70 K₂O/R₂O 0.50 0.50 0.84 0.28 0.50 0.69 0.30 0.30 0.30 R₂O + B₂O₃ (mol %) 8.3 10.4 14.4 14.5 14.5 14.5 14.4 14.4 14.4 SiO₂ + Al₂O₃ (mol %) 73.7 73.5 73.9 73.4 73.4 73.4 73.9 73.9 73.9 FeO (mol %) — — — — — — 0.0009 0.0001 0.0001 Fe-Redox (%) — — — — — — 22 2 3 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 37% 31% 28% 30% 33% 32% 31% 31% 31% at 100 GHz d 2.57 2.51 2.48 2.49 2.49 2.48 2.49 2.49 2.49 α (×10⁻⁷/° C.) 69 84 95 96 98 99 95 95 95 E (GPa) 76 76 62 74 71 67 73 73 73 T_(g) (° C.) 604 612 603 549 562 583 547 547 547 T₂ (° C.) 1545 1499 1495 1458 1478 1494 1444 1444 1444 T₄ (° C.) 1110 1096 1089 1041 1061 1081 1031 1031 1031 T_(L) (° C.) — — 940 — — — 1000 1000 1000 T₄ − T_(L) (° C.) — — 149 — — — 31 31 31 Water resistance (mg) 0.29 0.31 0.26 0.28 0.30 0.29 0.29 0.29 0.29 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — 91.6 90.7 89.9 measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — 91.0 90.1 87.6 Ultraviolet transmittance T_(uv) measured value (%) — — — — — — 86.6 70.6 40.0 A × radio transmittance (area: 0.0009 m²) 0.0337 0.0277 0.0254 0.0270 0.0299 0.0286 0.0279 0.0279 0.0279 Radio transmittance/t (thickness: 3.85 mm) 9.7 8.0 7.3 7.8 8.6 8.3 8.1 8.1 8.1 β-OH (mm⁻¹) — — — — — — 0.18 0.13 0.16 Transmittance at wavelength 905 nm (%) — — — — — — 90.8 92.0 91.9 Transmittance at wavelength 1550 nm (%) — — — — — — 91.3 92.3 92.3 Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 108 Ex. 109 Ex. 110 Ex. 111 Ex. 112 Ex. 113 Ex. 114 Ex. 115 Ex. 116 Embodiment 3 3 3 3 3 4 4 4 4 SiO₂ (mol %) 72.40 72.40 72.40 72.39 72.38 66.00 65.94 61.94 65.94 Al₂O₃ (mol %) 1.51 1.51 1.51 1.51 1.51 3.00 3.00 7.00 3.00 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 0.10 0.10 0.10 0.10 0.10 4.70 6.25 0.50 7.00 CaO (mol %) 11.56 11.56 11.56 11.56 11.56 7.74 6.25 12.00 12.00 SrO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 6.17 6.17 6.17 4.00 Na₂O (mol %) 10.06 10.06 10.06 10.05 10.05 6.17 6.17 6.17 4.00 K₂O (mol %) 4.32 4.32 4.32 4.32 4.32 6.17 6.17 6.17 4.00 Fe₂O₃ (mol %) 0.004 0.004 0.004 0.004 0.004 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.0036 0.0108 0.0180 0.0359 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.0061 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 11.66 11.66 11.66 11.66 11.66 12.44 12.50 12.50 19.00 R₂O (mol %) 14.38 14.38 14.38 14.37 14.37 18.51 18.51 18.51 12.00 7Al₂O₃ + 3MgO (mol %) 10.9 10.9 10.9 10.9 10.9 35.1 39.8 50.5 42.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 10.9 10.9 10.9 10.9 10.9 10.4 15.1 25.8 26.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 11.7 11.7 11.7 11.7 11.7 12.4 12.5 12.5 19.0 R₂O × MgO (mol %)² 1.4 1.4 1.4 1.4 1.4 87.0 115.7 9.3 84.0 Na₂O/R₂O 0.70 0.70 0.70 0.70 0.70 0.33 0.33 0.33 0.33 K₂O/R₂O 0.30 0.30 0.30 0.30 0.30 0.33 0.33 0.33 0.33 R₂O + B₂O₃ (mol %) 14.4 14.4 14.4 14.4 14.4 18.5 18.5 18.5 12.0 SiO₂ + Al₂O₃ (mol %) 73.9 73.9 73.9 73.9 73.9 69.0 68.9 68.9 68.9 FeO (mol %) 0.0002 0.0007 0.0003 0.0003 0.0003 — — — — Fe-Redox (%) 4 18 6.5 7 9 — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 31% 31% 31% 31% 31% 38% 39% 36% 36% at 100 GHz d 2.49 2.49 2.49 2.49 2.49 2.53 2.53 2.53 2.53 α (×10⁻⁷/° C.) 95 95 95 95 95 101 104 104 85 E (GPa) 73 73 73 73 73 78 78 78 83 T_(g) (° C.) 547 547 547 547 547 473 469 502 533 T₂ (° C.) 1444 1444 1444 1444 1444 1363 1362 1363 1398 T₄ (° C.) 1031 1031 1031 1031 1031 952 956 967 1015 T_(L) (° C.) 1000 1000 1000 1000 1000 — 920 1100 — T₄ − T_(L) (° C.) 31 31 31 31 31 — 36 −133 — Water resistance (mg) 0.29 0.29 0.29 0.29 0.29 0.21 0.20 0.20 0.13 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) 88.9 91.9 91.9 91.8 91.9 — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) 86.5 91.0 91.0 90.8 90.7 — — — — Ultraviolet transmittance T_(uv) measured value (%) 33.2 77.8 68.0 62.4 54.8 — — — — A × radio transmittance (area: 0.0009 m²) 0.0279 0.0279 0.0279 0.0279 0.0279 0.0345 0.0349 0.0324 0.0323 Radio transmittance/t (thickness: 3.85 mm) 8.1 8.1 8.1 8.1 8.1 9.9 10.1 9.4 9.3 β-OH (mm⁻¹) 0.19 0.17 0.08 0.25 0.23 — — — — Transmittance at wavelength 905 nm (%) 92.0 91.2 91.8 91.8 91.8 — — — — Transmittance at wavelength 1550 nm (%) 92.3 91.6 92.1 92.1 92.1 — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 117 Ex. 118 Ex. 119 Ex. 120 Ex. 121 Ex. 122 Ex. 123 Ex. 124 Ex. 125 Embodiment 4 4 4 4 4 4 4 4 4 SiO₂ (mol %) 65.94 67.03 67.03 64.73 66.03 66.03 66.03 66.53 66.53 Al₂O₃ (mol %) 3.00 1.90 3.90 4.00 7.50 7.50 8.50 4.50 5.50 B₂O₃ (mol %) 0.00 0.00 0.00 1.80 0.00 0.00 0.00 0.00 0.50 MgO (mol %) 9.50 1.50 0.00 3.40 4.30 4.30 4.30 3.80 4.30 CaO (mol %) 9.50 12.00 13.50 10.00 9.10 12.10 12.10 14.10 10.60 SrO (mol %) 0.00 2.00 0.00 0.00 0.00 0.00 0.00 1.50 4.00 BaO (mol %) 0.00 1.00 1.00 0.00 0.00 0.00 0.00 0.50 1.00 TiO₂ (mol %) 0.04 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.50 0.00 0.00 0.00 0.00 0.00 1.50 Li₂O (mol %) 4.00 1.50 1.70 3.00 2.00 2.00 2.00 2.00 2.00 Na₂O (mol %) 4.00 7.00 6.50 6.00 5.00 3.40 3.40 3.40 2.00 K₂O (mol %) 4.00 6.00 5.80 7.00 6.00 4.60 3.60 3.60 2.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 19.00 16.50 14.50 13.40 13.40 16.40 16.40 19.90 19.90 R₂O (mol %) 12.00 14.50 14.00 16.00 13.00 10.00 9.00 9.00 6.00 7Al₂O₃ + 3MgO (mol %) 49.5 17.8 27.3 38.2 65.4 65.4 72.4 42.9 51.4 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 33.5 11.8 20.5 26.2 57.4 57.4 64.4 34.9 43.4 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 99.5 98.2 100.0 100.0 100.0 100.0 98.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 19.0 13.5 13.5 13.4 13.4 16.4 16.4 17.9 14.9 R₂O × MgO (mol %)² 114.0 21.8 0.0 54.4 55.9 43.0 38.7 34.2 25.8 Na₂O/R₂O 0.33 0.48 0.46 0.38 0.38 0.34 0.38 0.38 0.33 K₂O/R₂O 0.33 0.41 0.41 0.44 0.46 0.46 0.40 0.40 0.33 R₂O + B₂O₃ (mol %) 12.0 14.5 14.0 17.8 13.0 10.0 9.0 9.0 6.5 SiO₂ + Al₂O₃ (mol %) 68.9 68.9 70.9 68.7 73.5 73.5 74.5 71.0 72.0 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 34% 36% 32% 39% 30% 31% 30% 32% 34% at 100 GHz d 2.53 2.61 2.56 2.52 2.50 2.51 2.51 2.59 2.67 α (×10⁻⁷/° C.) 84 102 95 97 86 78 74 79 64 E (GPa) 83 75 76 73 77 80 82 82 83 T_(g) (° C.) 576 524 561 510 599 630 645 606 642 T₂ (° C.) 1411 1366 1435 1384 1538 1541 1569 1463 1540 T₄ (° C.) 1024 977 1034 996 1138 1156 1184 1084 1155 T_(L) (° C.) 1170 — — — — — — — — T₄ − T_(L) (° C.) −146 — — — — — — — — Water resistance (mg) 0.09 0.26 0.26 0.16 — — — 0.13 0.09 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0305 0.0321 0.0292 0.0349 0.0272 0.0277 0.0274 0.0289 0.0326 Radio transmittance/t (thickness: 3.85 mm) 8.8 9.3 8.4 10.1 7.9 8.0 7.9 8.3 9.4 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 126 Ex. 127 Ex. 128 Ex. 129 Ex. 130 Ex. 131 Ex. 132 Ex. 133 Ex. 134 Embodiment 4 4 4 4 4 4 4 4 4 SiO₂ (mol %) 67.03 67.03 66.03 67.03 67.03 67.63 70.43 70.43 70.93 Al₂O₃ (mol %) 6.00 6.00 8.00 5.00 3.00 3.00 4.00 4.00 4.00 B₂O₃ (mol %) 1.00 0.50 0.50 2.00 1.80 1.20 0.00 0.00 0.00 MgO (mol %) 10.00 5.50 5.50 12.00 14.00 8.00 0.00 0.00 4.00 CaO (mol %) 2.40 13.60 7.60 4.90 2.10 5.10 17.50 17.50 7.00 SrO (mol %) 0.00 1.00 3.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.30 0.30 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 4.50 2.00 3.00 3.00 4.00 5.00 4.00 4.00 5.00 Na₂O (mol %) 4.50 2.00 3.00 3.00 4.00 5.00 0.00 3.10 5.00 K₂O (mol %) 4.50 2.00 3.00 3.00 4.00 5.00 4.00 0.90 4.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 12.40 20.40 16.40 16.90 16.10 13.10 17.50 17.50 11.00 R₂O (mol %) 13.50 6.00 9.00 9.00 12.00 15.00 8.00 8.00 14.00 7Al₂O₃ + 3MgO (mol %) 72.0 58.5 72.5 71.0 63.0 45.0 28.0 28.0 40.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 54.0 50.5 60.5 59.0 47.0 25.0 12.0 12.0 20.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 99.0 99.5 99.5 98.0 98.2 98.8 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 12.4 19.1 13.1 16.9 16.1 13.1 17.5 17.5 11.0 R₂O × MgO (mol %)² 135.0 33.0 49.5 108.0 168.0 120.0 0.0 0.0 56.0 Na₂O/R₂O 0.33 0.33 0.33 0.33 0.33 0.33 0.00 0.39 0.36 K₂O/R₂O 0.33 0.33 0.33 0.33 0.33 0.33 0.50 0.11 0.29 R₂O + B₂O₃ (mol %) 14.5 6.5 9.5 11.0 13.8 16.2 8.0 8.0 14.0 SiO₂ + Al₂O₃ (mol %) 73.0 73.0 74.0 72.0 70.0 70.6 74.4 74.4 74.9 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 33% 34% 32% 36% 36% 36% 31% 30% 32% at 100 GHz d 2.46 2.56 2.58 2.48 2.47 2.48 2.51 2.52 2.46 α (×10⁻⁷/° C.) 79 65 72 66 76 88 71 68 83 E (GPa) 80 84 82 81 80 78 82 84 79 T_(g) (° C.) 543 641 612 577 530 497 610 596 524 T₂ (° C.) 1524 1538 1549 1516 1439 1437 1529 1515 1540 T₄ (° C.) 1097 1153 1159 1106 1032 1015 1153 1123 1093 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) — — — — 0.02 0.17 0.32 0.33 0.21 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0300 0.0308 0.0291 0.0320 0.0323 0.0328 0.0276 0.0267 0.0292 Radio transmittance/t (thickness: 3.85 mm) 8.7 8.9 8.4 9.2 9.3 9.5 8.0 7.7 8.4 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 135 Ex. 136 Ex. 137 Ex. 138 Ex. 139 Ex. 140 Ex. 141 Ex. 142 Ex. 143 Embodiment 5 5 5 5 5 5 5 5 5 SiO₂ (mol %) 65.50 66.00 66.00 68.45 68.45 66.00 66.00 66.00 66.00 Al₂O₃ (mol %) 3.45 2.95 2.95 5.00 7.00 1.00 2.95 3.85 2.95 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.50 1.00 1.90 MgO (mol %) 0.50 0.50 6.00 0.50 0.00 7.00 0.00 0.10 3.50 CaO (mol %) 11.98 11.98 6.48 8.98 8.98 6.43 11.98 12.38 8.98 SrO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 1.00 0.00 0.00 0.00 Li₂O (mol %) 4.37 3.07 7.37 6.87 9.87 7.37 3.17 5.47 5.47 Na₂O (mol %) 8.97 8.97 8.97 7.97 3.47 2.17 2.17 7.97 7.97 K₂O (mol %) 5.17 6.47 2.17 2.17 2.17 8.97 13.17 3.17 3.17 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 12.48 12.48 12.48 9.48 8.98 13.43 11.98 12.48 12.48 R₂O (mol %) 18.51 18.51 18.51 17.01 15.51 18.51 18.51 16.61 16.61 7Al₂O₃ + 3MgO (mol %) 25.7 22.2 38.7 36.5 49.0 28.0 20.7 27.3 31.2 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 8.2 9.9 9.2 9.0 9.5 −1.5 8.0 5.4 9.3 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 99.0 99.5 99.0 98.1 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 12.5 12.5 12.5 9.5 9.0 13.4 12.0 12.5 12.5 R₂O × MgO (mol %)² 9.3 9.3 111.1 8.5 0.0 129.6 0.0 1.7 58.1 Na₂O/R₂O 0.48 0.48 0.48 0.47 0.22 0.12 0.12 0.48 0.48 K₂O/R₂O 0.28 0.35 0.12 0.13 0.14 0.48 0.71 0.19 0.19 R₂O + B₂O₃ (mol %) 18.5 18.5 18.5 17.0 15.5 18.5 19.0 17.6 18.5 SiO₂ + Al₂O₃ (mol %) 69.0 69.0 69.0 73.5 75.5 67.0 69.0 69.9 69.0 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 39% 40% 35% 32% 33% 35% 31% 37% 39% at 100 GHz d 2.52 2.52 2.49 2.49 2.47 2.51 2.51 2.52 2.51 α (×10⁻⁷/° C.) 106 108 97 90 80 100 106 96 94 E (GPa) 77 74 83 81 85 76 61 79 79 T_(g) (° C.) 484 490 467 491 503 475 524 488 470 T₂ (° C.) 1349 1354 1364 1453 1507 1336 1340 1362 1363 T₄ (° C.) 935 947 929 1010 1068 940 995 946 944 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.19 0.21 0.25 0.23 0.39 0.20 0.24 0.22 0.23 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0349 0.0357 0.0317 0.0290 0.0294 0.0314 0.0277 0.0330 0.0348 Radio transmittance/t (thickness: 3.85 mm) 10.1 10.3 9.1 8.4 8.5 9.1 8.0 9.5 10.1 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 144 Ex. 145 Ex. 146 Ex. 147 Ex. 148 Ex. 149 Ex. 150 Ex. 151 Ex. 152 Embodiment 5 5 5 5 5 5 5 6 6 SiO₂ (mol %) 69.00 70.50 69.50 69.00 69.00 69.50 69.03 66.00 67.95 Al₂O₃ (mol %) 2.95 2.50 2.95 2.95 3.20 2.95 3.50 5.50 5.50 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.95 0.00 MgO (mol %) 0.00 2.00 0.10 1.50 1.00 4.50 0.90 0.50 0.50 CaO (mol %) 2.50 9.43 5.50 2.00 11.98 10.48 8.00 11.98 11.98 SrO (mol %) 9.48 0.00 5.48 11.98 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.90 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 5.17 5.17 5.17 4.17 8.08 8.33 6.17 13.00 13.00 Na₂O (mol %) 5.17 5.17 5.17 4.17 4.17 0.80 6.17 1.00 1.00 K₂O (mol %) 5.17 5.17 5.17 4.17 2.50 3.37 6.17 0.00 0.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 11.98 11.43 11.98 15.48 12.98 14.98 8.90 12.48 12.48 R₂O (mol %) 15.51 15.51 15.51 12.51 14.75 12.50 18.51 14.00 14.00 7Al₂O₃ + 3MgO (mol %) 20.7 23.5 21.0 25.2 25.4 34.2 27.2 40.0 40.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 0.0 2.8 0.3 8.5 −6.9 0.8 2.5 −12.0 −12.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 99.5 100.0 100.0 100.0 100.0 100.0 100.0 98.1 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 2.5 11.4 5.6 3.5 13.0 15.0 8.9 12.5 12.5 R₂O × MgO (mol %)² 0.0 31.0 1.6 18.8 14.8 56.3 16.7 7.0 7.0 Na₂O/R₂O 0.33 0.33 0.33 0.33 0.28 0.06 0.33 0.07 0.07 K₂O/R₂O 0.33 0.33 0.33 0.33 0.17 0.27 0.33 0.00 0.00 R₂O + B₂O₃ (mol %) 15.5 15.5 15.5 12.5 14.8 12.5 18.5 16.0 14.0 SiO₂ + Al₂O₃ (mol %) 72.0 73.0 72.5 72.0 72.2 72.5 72.5 71.5 73.5 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 37% 35% 37% 36% 33% 32% 39% 33% 31% at 100 GHz d 2.68 2.48 2.62 2.71 2.50 2.48 2.48 2.50 2.49 α (×10⁻⁷/° C.) 96 92 96 90 85 77 99 72 72 E (GPa) 78 78 77 79 84 85 85 90 92 T_(g) (° C.) 486 500 479 511 494 509 473 479 500 T₂ (° C.) 1408 1462 1421 1422 1427 1478 1431 1383 1458 T₄ (° C.) 996 1036 1000 1017 1006 1054 1001 959 1019 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.28 0.28 0.28 0.26 0.27 0.13 0.23 0.31 0.33 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0331 0.0311 0.0331 0.0322 0.0297 0.0291 0.0347 0.0301 0.0283 Radio transmittance/t (thickness: 3.85 mm) 9.5 9.0 9.5 9.3 8.6 8.4 10.0 8.7 8.2 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 153 Ex. 154 Ex. 155 Ex. 156 Ex. 157 Ex. 158 Ex. 159 Ex. 160 Ex. 161 Embodiment 6 6 6 6 6 6 6 6 6 SiO₂ (mol %) 66.85 66.85 66.85 69.95 70.75 70.75 70.75 70.75 70.75 Al₂O₃ (mol %) 5.00 4.00 3.00 2.00 1.00 1.00 1.00 1.00 1.00 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MgO (mol %) 0.50 1.00 0.50 0.50 0.20 10.00 8.00 6.00 4.00 CaO (mol %) 13.58 13.58 11.58 13.48 13.48 3.68 3.68 4.68 6.68 SrO (mol %) 0.00 0.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 1.00 0.00 0.00 0.00 0.00 0.00 2.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 14.00 13.00 10.00 14.00 14.50 13.50 12.50 9.50 7.50 Na₂O (mol %) 0.00 0.75 3.00 0.00 0.00 0.50 2.00 4.00 4.00 K₂O (mol %) 0.00 0.75 3.00 0.00 0.00 0.50 2.00 4.00 4.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 14.08 14.58 14.08 13.98 13.68 13.68 11.68 10.68 12.68 R₂O (mol %) 14.00 14.50 16.00 14.00 14.50 14.50 16.50 17.50 15.50 7Al₂O₃ + 3MgO (mol %) 36.5 31.0 22.5 15.5 7.6 37.0 31.0 25.0 19.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) −19.5 −21.0 −17.5 −40.5 −50.4 −17.0 −19.0 −13.0 −11.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 14.1 14.6 12.1 14.0 13.7 13.7 11.7 10.7 10.7 R₂O × MgO (mol %)² 7.0 14.5 8.0 7.0 2.9 145.0 132.0 105.0 62.0 Na₂O/R₂O 0.00 0.05 0.19 0.00 0.00 0.03 0.12 0.23 0.26 K₂O/R₂O 0.00 0.05 0.19 0.00 0.00 0.03 0.12 0.23 0.26 R₂O + B₂O₃ (mol %) 14.0 14.5 16.0 14.0 14.5 14.5 16.5 17.5 15.5 SiO₂ + Al₂O₃ (mol %) 71.9 70.9 69.9 72.0 71.8 71.8 71.8 71.8 71.8 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 31% 32% 35% 31% 31% 35% 37% 39% 37% at 100 GHz d 2.50 2.50 2.56 2.49 2.48 2.44 2.44 2.45 2.53 α (×10⁻⁷/° C.) 73 78 91 72 73 68 79 90 90 E (GPa) 94 93 85 93 93 92 92 83 81 T_(g) (° C.) 499 491 466 490 487 480 469 458 459 T₂ (° C.) 1400 1374 1338 1434 1433 1486 1466 1442 1435 T₄ (° C.) 974 953 928 994 989 989 980 983 989 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.30 0.26 0.25 0.20 0.17 0.15 0.19 0.33 0.31 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0281 0.0287 0.0317 0.0276 0.0277 0.0318 0.0337 0.0350 0.0329 Radio transmittance/t (thickness: 3.85 mm) 8.1 8.3 9.1 8.0 8.0 9.2 9.7 10.1 9.5 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 162 Ex. 163 Ex. 164 Ex. 165 Ex. 166 Ex. 167 Ex. 168 Ex. 169 Ex. 170 Embodiment 6 6 6 6 6 6 6 6 6 SiO₂ (mol %) 70.75 69.95 69.95 69.95 70.85 70.85 71.35 69.85 70.85 Al₂O₃ (mol %) 1.00 2.00 2.00 2.00 1.00 1.00 0.50 1.00 1.00 B₂O₃ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 0.00 MgO (mol %) 2.00 0.50 0.50 0.50 0.20 0.20 0.10 0.20 0.20 CaO (mol %) 6.18 13.48 13.48 13.48 14.38 14.38 12.38 1.00 1.00 SrO (mol %) 2.00 0.00 0.00 0.00 0.00 0.00 0.00 13.38 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 2.10 0.00 13.38 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 6.00 7.00 7.00 7.00 4.50 4.50 4.50 4.50 4.50 Na₂O (mol %) 6.00 7.00 0.00 3.50 4.50 4.50 4.50 4.50 4.50 K₂O (mol %) 6.00 0.00 7.00 3.50 4.50 4.50 4.50 4.50 4.50 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 10.18 13.98 13.98 13.98 14.58 14.58 14.58 14.58 14.58 R₂O (mol %) 18.00 14.00 14.00 14.00 13.50 13.50 13.50 13.50 13.50 7Al₂O₃ + 3MgO (mol %) 13.0 15.5 15.5 15.5 7.6 7.6 3.8 7.6 7.6 7Al₂O₃ + 3MgO − 4Li₂O (mol %) −11.0 −12.5 −12.5 −12.5 −10.4 −10.4 −14.2 −10.4 −10.4 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 100.0 100.0 100.0 100.0 100.0 99.0 100.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 8.2 14.0 14.0 14.0 14.6 14.6 12.5 1.2 1.2 R₂O × MgO (mol %)² 36.0 7.0 7.0 7.0 2.7 2.7 1.4 2.7 2.7 Na₂O/R₂O 0.33 0.50 0.00 0.25 0.33 0.33 0.33 0.33 0.33 K₂O/R₂O 0.33 0.00 0.50 0.25 0.33 0.33 0.33 0.33 0.33 R₂O + B₂O₃ (mol %) 18.0 14.0 14.0 14.0 13.5 13.5 13.5 14.5 13.5 SiO₂ + Al₂O₃ (mol %) 71.8 72.0 72.0 72.0 71.9 71.9 71.9 70.9 71.9 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 40% 30% 30% 33% 33% 33% 34% 40% 41% at 100 GHz d 2.52 2.51 2.49 2.50 2.50 2.50 2.56 2.72 2.93 α (×10⁻⁷/° C.) 101 83 88 86 90 90 92 95 101 E (GPa) 76 84 78 82 79 79 78 77 73 T_(g) (° C.) 454 501 517 501 518 518 493 462 478 T₂ (° C.) 1405 1405 1434 1420 1415 1415 1411 1362 1415 T₄ (° C.) 976 988 1048 1015 1021 1021 1003 959 924 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.32 0.28 0.20 0.26 0.27 0.27 0.26 0.25 0.27 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0363 0.0269 0.0268 0.0295 0.0296 0.0296 0.0308 0.0364 0.0370 Radio transmittance/t (thickness: 3.85 mm) 10.5 7.8 7.7 8.5 8.5 8.5 8.9 10.5 10.7 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 171 Ex. 172 Ex. 173 Ex. 174 Ex. 175 Ex. 176 Ex. 177 Ex. 178 Ex. 179 Embodiment 6 6 6 6 6 6 1 1 1 SiO₂ (mol %) 70.85 70.85 67.35 69.95 69.95 69.95 68.06 65.06 65.06 Al₂O₃ (mol %) 1.20 1.00 1.00 2.00 2.00 2.00 6.00 6.00 5.00 B₂O₃ (mol %) 0.00 0.00 0.50 0.00 0.00 0.00 4.00 7.00 5.00 MgO (mol %) 0.00 0.20 0.20 0.50 0.50 0.50 0.10 5.10 9.10 CaO (mol %) 0.00 10.38 9.38 13.48 13.48 13.48 0.00 2.60 0.00 SrO (mol %) 7.19 2.00 4.00 0.00 0.00 0.00 7.60 0.00 2.60 BaO (mol %) 7.19 2.00 4.00 0.00 0.00 0.00 0.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 5.00 4.50 4.50 12.00 10.00 8.00 0.00 0.00 0.00 Na₂O (mol %) 4.25 4.50 4.50 1.00 2.00 3.00 10.52 9.02 4.02 K₂O (mol %) 4.25 4.50 4.50 1.00 2.00 3.00 3.65 5.15 9.15 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 14.38 14.58 17.58 13.98 13.98 13.98 7.70 7.70 11.70 R₂O (mol %) 13.50 13.50 13.50 14.00 14.00 14.00 14.17 14.17 13.17 7Al₂O₃ + 3MgO (mol %) 8.4 7.6 7.6 15.5 15.5 15.5 42.3 57.3 62.3 7Al₂O₃ + 3MgO − 4Li₂O (mol %) −11.6 −10.4 −10.4 −32.5 −24.5 −16.5 42.3 57.3 62.3 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 100.0 100.0 99.5 100.0 100.0 100.0 96.0 93.0 95.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 0.0 10.6 9.6 14.0 14.0 14.0 0.1 7.7 9.1 R₂O × MgO (mol %)² 0.0 2.7 2.7 7.0 7.0 7.0 1.4 72.3 119.8 Na₂O/R₂O 0.31 0.33 0.33 0.07 0.14 0.21 0.74 0.64 0.31 K₂O/R₂O 0.31 0.33 0.33 0.07 0.14 0.21 0.26 0.36 0.69 R₂O + B₂O₃ (mol %) 13.5 13.5 14.0 14.0 14.0 14.0 18.2 21.2 18.2 SiO₂ + Al₂O₃ (mol %) 72.1 71.9 68.4 72.0 72.0 72.0 74.1 71.1 70.1 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 40% 35% 38% 31% 32% 33% 34% 42% 41% at 100 GHz d 2.77 2.60 2.73 2.49 2.49 2.50 2.64 2.49 2.54 α (×10⁻⁷/° C.) 98 93 99 76 80 84 87 81 84 E (GPa) 76 78 78 90 87 84 69 66 65 T_(g) (° C.) 452 489 462 487 489 496 550 531 572 T₂ (° C.) 1406 1411 1306 1426 1421 1420 1502 1507 1480 T₄ (° C.) 948 1000 920 1000 1005 1012 1058 1079 1097 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.26 0.27 0.23 0.22 0.24 0.26 0.13 — — Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0360 0.0313 0.0339 0.0283 0.0289 0.0293 0.0308 0.0377 0.0367 Radio transmittance/t (thickness: 3.85 mm) 10.4 9.0 9.8 8.2 8.3 8.5 8.9 10.9 10.6 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 180 Ex. 181 Ex. 182 Ex. 183 Ex. 184 Ex. 185 Ex. 186 Ex. 187 Ex. 188 Embodiment 1 1 1 2 2 2 2 2 2 SiO₂ (mol %) 62.06 65.80 65.80 70.45 67.45 69.45 69.45 67.45 70.03 Al₂O₃ (mol %) 9.00 7.00 7.00 4.00 3.50 5.00 5.80 5.00 5.80 B₂O₃ (mol %) 7.00 10.00 12.00 4.00 5.00 6.00 8.00 10.00 5.00 MgO (mol %) 0.00 1.13 5.00 0.00 0.00 0.00 0.00 1.80 0.00 CaO (mol %) 0.00 8.00 4.63 11.99 8.99 9.99 7.69 5.69 0.00 SrO (mol %) 0.00 0.00 0.00 0.00 3.50 0.00 0.00 0.00 2.00 BaO (mol %) 7.70 0.00 0.00 0.00 0.00 0.00 1.00 0.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 1.50 0.50 1.50 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 5.02 4.00 1.50 5.49 4.20 4.20 6.10 7.20 4.10 K₂O (mol %) 9.15 4.00 4.00 2.50 6.80 3.80 1.90 2.80 13.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 7.70 9.13 9.63 11.99 12.49 9.99 8.69 7.49 2.00 R₂O (mol %) 14.17 8.00 5.50 7.99 11.00 8.00 8.00 10.00 17.10 7Al₂O₃ + 3MgO (mol %) 63.0 52.4 64.0 28.0 24.5 35.0 40.6 40.4 40.6 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 63.0 52.4 64.0 28.0 24.5 35.0 40.6 40.4 40.6 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 93.0 90.0 88.0 94.5 94.5 92.5 92.0 90.0 95.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 0.0 9.1 9.6 12.0 9.0 10.0 7.7 7.5 0.0 R₂O × MgO (mol %)² 0.0 9.0 27.5 0.0 0.0 0.0 0.0 18.0 0.0 Na₂O/R₂O 0.35 0.50 0.27 0.69 0.38 0.53 0.76 0.72 0.24 K₂O/R₂O 0.65 0.50 0.73 0.31 0.62 0.48 0.24 0.28 0.76 R₂O + B₂O₃ (mol %) 21.2 18.0 17.5 12.0 16.0 14.0 16.0 20.0 22.1 SiO₂ + Al₂O₃ (mol %) 71.1 72.8 72.8 74.5 71.0 74.5 75.3 72.5 75.8 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 47% 53% 54% 40% 44% 49% 47% 53% 41% at 100 GHz d 2.71 2.51 2.49 2.54 2.61 2.53 2.52 2.49 2.48 α (×10⁻⁷/° C.) 87 59 47 63 81 60 59 64 93 E (GPa) 59 67 66 75 68 72 68 65 52 T_(g) (° C.) 540 576 588 624 567 618 568 531 557 T₂ (° C.) 1477 1522 1552 1538 1448 1556 1555 1503 1557 T₄ (° C.) 1098 1127 1163 1132 1060 1148 1114 1067 1111 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.30 0.25 — 0.30 0.28 0.33 0.31 0.19 0.36 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0423 0.0478 0.0483 0.0350 0.0397 0.0439 0.0424 0.0474 0.0372 Radio transmittance/t (thickness: 3.85 mm) 12.2 13.8 14.0 10.1 11.4 12.7 12.2 13.7 10.7 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 189 Ex. 190 Ex. 191 Ex. 192 Ex. 193 Ex. 194 Ex. 195 Ex. 196 Ex. 197 Embodiment 2 2 2 2 3 3 3 3 3 SiO₂ (mol %) 66.03 66.03 68.13 69.13 72.01 67.01 72.01 69.41 70.41 Al₂O₃ (mol %) 5.80 4.00 2.80 3.80 2.80 1.50 2.00 2.00 2.00 B₂O₃ (mol %) 12.00 9.00 7.00 6.00 6.00 10.00 5.00 7.00 7.00 MgO (mol %) 0.00 1.80 3.00 2.00 1.00 3.00 3.00 1.00 3.00 CaO (mol %) 0.00 0.00 0.00 5.00 0.00 6.56 5.56 5.73 0.00 SrO (mol %) 0.00 0.00 0.00 0.00 3.56 0.00 2.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 2.00 0.00 0.00 0.00 3.71 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.04 0.04 0.04 0.04 0.04 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.20 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 12.00 15.00 10.00 7.00 9.55 8.65 7.15 11.80 10.00 K₂O (mol %) 4.10 4.10 9.00 7.00 2.82 3.22 3.22 3.00 3.82 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 0.00 1.80 3.00 7.00 6.56 9.56 10.56 6.73 6.71 R₂O (mol %) 16.10 19.10 19.00 14.00 12.37 11.87 10.37 14.80 13.82 7Al₂O₃ + 3MgO (mol %) 40.6 33.4 28.6 32.6 22.6 19.5 23.0 17.0 23.0 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 40.6 33.4 28.6 32.6 22.6 19.5 23.0 17.0 23.0 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 88.0 91.0 93.0 94.0 93.8 90.0 95.0 93.0 93.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 0.0 1.8 3.0 7.0 1.0 9.6 8.6 6.7 3.0 R₂O × MgO (mol %)² 0.0 34.4 57.0 28.0 12.4 35.6 31.1 14.8 41.5 Na₂O/R₂O 0.75 0.79 0.53 0.50 0.77 0.73 0.69 0.80 0.72 K₂O/R₂O 0.25 0.21 0.47 0.50 0.23 0.27 0.31 0.20 0.28 R₂O + B₂O₃ (mol %) 28.1 28.1 26.0 20.0 18.4 21.9 15.4 21.8 20.8 SiO₂ + Al₂O₃ (mol %) 71.8 70.0 70.9 72.9 74.8 68.5 74.0 71.4 72.4 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 44% 31% 56% 47% 44% 56% 42% 40% 48% at 100 GHz d 2.48 2.48 2.46 2.48 2.58 2.51 2.52 2.49 2.57 α (×10⁻⁷/° C.) 78 94 99 84 78 76 73 86 84 E (GPa) 58 61 57 64 66 65 70 64 63 T_(g) (° C.) 461 440 454 525 505 479 542 477 468 T₂ (° C.) 1477 1436 1438 1496 1495 1386 1510 1417 1460 T₄ (° C.) 1012 972 990 1056 1023 969 1062 977 985 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.04 0.02 0.26 0.24 0.28 0.31 0.34 0.23 0.28 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0398 0.0283 0.0505 0.0421 0.0394 0.0499 0.0381 0.0351 0.0398 Radio transmittance/t (thickness: 3.85 mm) 11.5 8.2 14.6 12.1 11.4 14.4 11.0 10.1 11.5 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 198 Ex. 199 Ex. 200 Ex. 201 Ex. 202 Ex. 203 Ex. 204 Ex. 205 Ex. 206 Embodiment 3 7 7 7 7 7 7 7 7 SiO₂ (mol %) 70.71 67.03 67.93 67.93 67.93 66.93 65.93 65.93 60.93 Al₂O₃ (mol %) 3.00 1.90 3.00 2.00 3.00 3.00 3.00 3.00 8.70 B₂O₃ (mol %) 6.50 4.00 3.00 3.00 3.00 4.00 5.00 7.00 7.00 MgO (mol %) 0.20 1.50 1.50 12.00 8.00 6.00 1.50 1.50 1.50 CaO (mol %) 10.71 8.00 5.00 3.00 6.00 6.50 2.00 6.00 6.00 SrO (mol %) 0.00 2.00 6.00 0.00 0.00 0.00 8.00 0.00 0.00 BaO (mol %) 0.00 1.00 0.00 0.00 0.00 0.00 1.00 1.00 0.00 TiO₂ (mol %) 0.04 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 1.50 1.00 4.00 4.00 4.50 1.00 2.00 13.50 Na₂O (mol %) 5.00 7.00 6.50 4.00 4.00 4.50 0.50 11.50 1.30 K₂O (mol %) 3.82 6.00 6.00 4.00 4.00 4.50 12.00 2.00 1.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 10.91 12.50 12.50 15.00 14.00 12.50 12.50 8.50 7.50 R₂O (mol %) 8.82 14.50 13.50 12.00 12.00 13.50 13.50 15.50 15.80 7Al₂O₃ + 3MgO (mol %) 21.6 17.8 25.5 50.0 45.0 39.0 25.5 25.5 65.4 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 21.6 11.8 21.5 34.0 29.0 21.0 21.5 17.5 11.4 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 93.5 96.0 97.0 97.0 97.0 96.0 95.0 93.0 93.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 10.9 9.5 6.5 15.0 14.0 12.5 3.5 7.5 7.5 R₂O × MgO (mol %)² 1.8 21.8 20.3 144.0 96.0 81.0 20.3 23.3 23.7 Na₂O/R₂O 0.57 0.48 0.48 0.33 0.33 0.33 0.04 0.74 0.08 K₂O/R₂O 0.43 0.41 0.44 0.33 0.33 0.33 0.89 0.13 0.06 R₂O + B₂O₃ (mol %) 15.3 18.5 16.5 15.0 15.0 17.5 18.5 22.5 22.8 SiO₂ + Al₂O₃ (mol %) 73.7 68.9 70.9 69.9 70.9 69.9 68.9 68.9 69.6 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 46% 46% 41% 39% 38% 41% 32% 41% 41% at 100 GHz d 2.50 2.59 2.63 2.47 2.48 2.49 2.67 2.54 2.49 α (×10⁻⁷/° C.) 68 94 92 76 76 81 91 87 72 E (GPa) 69 70 71 78 78 76 59 69 84 T_(g) (° C.) 565 483 519 509 514 486 522 452 429 T₂ (° C.) 1506 1366 1423 1432 1458 1415 1367 1381 1290 T₄ (° C.) 1082 965 1016 1016 1039 1004 1032 940 899 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.30 0.26 0.25 0.22 0.13 0.17 0.17 0.18 0.25 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0412 0.0411 0.0372 0.0350 0.0344 0.0372 0.0286 0.0366 0.0372 Radio transmittance/t (thickness: 3.85 mm) 11.9 11.9 10.7 10.1 9.9 10.7 8.2 10.6 10.7 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 207 Ex. 208 Ex. 209 Ex. 210 Ex. 211 Ex. 212 Ex. 213 Ex. 214 Ex. 215 Embodiment 7 7 7 7 7 7 7 7 7 SiO₂ (mol %) 60.93 64.63 65.93 65.93 65.93 60.93 66.03 66.03 66.53 Al₂O₃ (mol %) 8.70 6.00 6.00 5.00 5.00 8.70 8.50 6.50 4.00 B₂O₃ (mol %) 7.00 5.00 2.00 0.50 1.00 7.00 6.00 6.00 8.00 MgO (mol %) 1.50 1.50 3.00 3.00 3.00 5.00 4.30 4.30 4.80 CaO (mol %) 6.00 8.00 8.00 9.50 10.00 0.50 6.10 6.60 6.10 SrO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.50 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.00 1.00 0.00 0.00 0.00 1.50 0.00 Li₂O (mol %) 11.50 7.50 5.00 5.00 5.00 14.30 2.00 2.00 3.00 Na₂O (mol %) 2.30 4.30 5.00 5.00 5.00 0.50 3.40 3.40 3.40 K₂O (mol %) 2.00 3.00 5.00 5.00 5.00 2.00 3.60 3.60 3.60 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 1.00 0.00 0.00 0.00 RO (mol %) 7.50 9.50 11.00 12.50 13.00 5.50 10.40 10.90 11.40 R₂O (mol %) 15.80 14.80 15.00 15.00 15.00 16.80 9.00 9.00 10.00 7Al₂O₃ + 3MgO (mol %) 65.4 46.5 51.0 44.0 44.0 75.9 72.4 58.4 42.4 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 19.4 16.5 31.0 24.0 24.0 18.7 64.4 50.4 30.4 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 93.0 95.0 98.0 98.5 99.0 92.0 94.0 92.5 92.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 7.5 9.5 11.0 12.5 13.0 5.5 10.4 10.9 10.9 R₂O × MgO (mol %)² 23.7 22.2 45.0 45.0 45.0 84.0 38.7 38.7 48.0 Na₂O/R₂O 0.15 0.29 0.33 0.33 0.33 0.03 0.38 0.38 0.34 K₂O/R₂O 0.13 0.20 0.33 0.33 0.33 0.12 0.40 0.40 0.36 R₂O + B₂O₃ (mol %) 22.8 19.8 17.0 15.5 16.0 23.8 15.0 15.0 18.0 SiO₂ + Al₂O₃ (mol %) 69.6 70.6 71.9 70.9 70.9 69.6 74.5 72.5 70.5 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 44% 43% 37% 33% 35% 41% 41% 47% 48% at 100 GHz d 2.49 2.50 2.49 2.53 2.50 2.46 2.49 2.53 2.51 α (×10⁻⁷/° C.) 74 78 86 87 89 72 63 60 65 E (GPa) 81 78 77 80 79 83 74 75 72 T_(g) (° C.) 432 462 510 531 513 431 584 586 498 T₂ (° C.) 1310 1388 1455 1460 1425 1305 1569 1560 1446 T₄ (° C.) 927 980 1045 1046 1022 909 1168 1151 1040 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.23 0.21 0.12 0.15 0.15 0.02 0.05 0.03 0.11 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0395 0.0385 0.0329 0.0296 0.0316 0.0367 0.0372 0.0427 0.0432 Radio transmittance/t (thickness: 3.85 mm) 11.4 11.1 9.5 8.5 9.1 10.6 10.7 12.3 12.5 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 216 Ex. 217 Ex. 218 Ex. 219 Ex. 220 Ex. 221 Ex. 222 Ex. 223 Ex. 224 Embodiment 7 7 7 8 8 8 8 8 8 SiO₂ (mol %) 67.53 62.53 62.53 66.00 66.00 66.30 66.33 66.43 67.30 Al₂O₃ (mol %) 4.00 7.00 5.00 2.95 3.95 4.15 7.50 5.00 5.00 B₂O₃ (mol %) 10.00 12.00 9.00 8.00 6.00 4.00 2.00 1.00 3.00 MgO (mol %) 2.80 2.80 1.00 0.50 0.50 2.98 0.10 2.00 0.10 CaO (mol %) 6.10 2.10 1.00 6.98 7.98 5.00 8.00 5.00 5.00 SrO (mol %) 0.00 4.00 9.50 0.00 0.00 0.00 0.00 2.00 3.33 BaO (mol %) 0.00 0.00 0.00 0.00 0.00 0.50 0.00 1.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.00 0.00 0.50 0.00 0.00 0.00 0.00 0.00 0.50 Li₂O (mol %) 5.00 5.00 5.00 4.40 5.17 9.50 11.00 8.00 8.80 Na₂O (mol %) 1.40 1.40 2.00 2.17 7.17 5.60 2.50 6.50 5.20 K₂O (mol %) 3.10 3.10 4.40 8.94 3.16 1.90 2.50 3.00 1.70 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 8.90 8.90 11.50 7.48 8.48 8.48 8.10 10.00 8.43 R₂O (mol %) 9.50 9.50 11.40 15.51 15.50 17.00 16.00 17.50 15.70 7Al₂O₃ + 3MgO (mol %) 36.4 57.4 38.0 22.2 29.2 38.0 52.8 41.0 35.3 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 16.4 37.4 18.0 4.6 8.5 0.0 8.8 9.0 0.1 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 90.0 88.0 90.5 92.0 94.0 96.0 98.0 99.0 96.5 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 8.9 4.9 2.0 7.5 8.5 8.0 8.1 7.0 5.1 R₂O × MgO (mol %)² 26.6 26.6 11.4 7.8 7.8 50.7 1.6 35.0 1.6 Na₂O/R₂O 0.15 0.15 0.18 0.14 0.46 0.33 0.16 0.37 0.33 K₂O/R₂O 0.33 0.33 0.39 0.58 0.20 0.11 0.16 0.17 0.11 R₂O + B₂O₃ (mol %) 19.5 21.5 20.4 23.5 21.5 21.0 18.0 18.5 18.7 SiO₂ + Al₂O₃ (mol %) 71.5 69.5 67.5 69.0 70.0 70.5 73.8 71.4 72.3 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 46% 48% 50% 45% 48% 44% 37% 38% 40% at 100 GHz d 2.49 2.60 2.73 2.50 2.50 2.49 2.48 2.56 2.58 α (×10⁻⁷/° C.) 57 58 73 84 83 82 79 92 80 E (GPa) 71 70 72 63 73 81 84 81 83 T_(g) (° C.) 465 465 461 447 449 435 478 462 468 T₂ (° C.) 1449 1376 1317 1340 1373 1382 1449 1406 1423 T₄ (° C.) 1040 1041 991 970 951 932 1020 965 984 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.17 0.12 0.22 0.23 0.22 0.18 0.40 0.18 0.29 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0413 0.0433 0.0449 0.0402 0.0432 0.0387 0.0331 0.0343 0.0358 Radio transmittance/t (thickness: 3.85 mm) 11.9 12.5 13.0 11.6 12.5 11.2 9.5 9.9 10.3 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 225 Ex. 226 Ex. 227 Ex. 228 Ex. 229 Ex. 230 Ex. 231 Ex. 232 Ex. 233 Embodiment 8 8 8 9 9 9 9 9 9 SiO₂ (mol %) 67.30 70.30 70.30 69.95 69.95 69.95 65.93 67.85 69.95 Al₂O₃ (mol %) 4.00 1.45 2.00 2.00 1.00 3.50 1.00 0.80 1.00 B₂O₃ (mol %) 3.00 10.00 5.00 3.00 5.00 8.00 6.00 7.00 4.00 MgO (mol %) 1.00 3.48 4.13 0.50 0.50 0.50 0.00 0.20 7.98 CaO (mol %) 5.00 2.00 5.00 10.48 7.48 0.00 3.50 4.38 0.00 SrO (mol %) 3.33 3.00 0.00 0.00 0.00 2.48 3.00 6.20 0.00 BaO (mol %) 0.00 0.00 0.00 0.00 1.00 0.00 7.00 0.00 1.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 ZrO₂ (mol %) 0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Li₂O (mol %) 9.50 4.50 4.50 8.00 10.00 11.00 4.50 6.00 11.00 Na₂O (mol %) 4.00 1.00 4.50 3.00 2.00 2.00 4.50 3.00 2.00 K₂O (mol %) 2.30 4.20 4.50 3.00 3.00 2.00 4.50 1.50 3.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.50 0.00 3.00 0.00 RO (mol %) 9.33 8.48 9.13 10.98 8.98 2.98 13.50 10.78 8.98 R₂O (mol %) 15.80 9.70 13.50 14.00 15.00 15.00 13.50 10.50 16.00 7Al₂O₃ + 3MgO (mol %) 31.0 20.6 26.4 15.5 8.5 26.0 7.0 6.2 30.9 7Al₂O₃ + 3MgO − 4Li₂O (mol %) −7.0 2.6 8.4 −16.5 −31.5 −18.0 −11.0 −17.8 −13.1 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 96.5 90.0 95.0 97.0 95.0 91.5 94.0 90.0 96.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 6.0 5.5 9.1 11.0 8.0 0.5 3.5 4.6 8.0 R₂O × MgO (mol %)² 15.8 33.8 55.8 7.0 7.5 7.5 0.0 2.1 127.7 Na₂O/R₂O 0.25 0.10 0.33 0.21 0.13 0.13 0.33 0.29 0.13 K₂O/R₂O 0.15 0.43 0.33 0.21 0.20 0.13 0.33 0.14 0.19 R₂O + B₂O₃ (mol %) 18.8 19.7 18.5 17.0 20.0 23.0 19.5 17.5 20.0 SiO₂ + Al₂O₃ (mol %) 71.3 71.8 72.3 72.0 71.0 73.5 66.9 68.7 71.0 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 41% 47% 45% 38% 42% 49% 53% 47% 44% at 100 GHz d 2.58 2.53 2.46 2.49 2.50 2.50 2.77 2.65 2.47 α (×10⁻⁷/° C.) 81 60 77 79 77 66 93 72 76 E (GPa) 82 69 73 80 78 73 70 79 81 T_(g) (° C.) 457 451 471 463 416 413 402 433 429 T₂ (° C.) 1401 1460 1465 1420 1386 1463 1265 1308 1435 T₄ (° C.) 965 1021 1023 999 949 984 867 918 950 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.26 0.18 0.28 0.26 0.21 0.30 0.21 0.20 0.24 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0373 0.0422 0.0404 0.0344 0.0380 0.0443 0.0476 0.0423 0.0400 Radio transmittance/t (thickness: 3.85 mm) 10.8 12.2 11.7 9.9 11.0 12.8 13.7 12.2 11.5 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 234 Ex. 235 Ex. 236 Ex. 237 Ex. 238 Ex. 239 Ex. 240 Ex. 241 Ex. 242 Embodiment 9 9 9 9 9 9 9 10 10 SiO₂ (mol %) 69.95 67.95 65.75 73.75 65.75 65.75 66.75 72.38 72.00 Al₂O₃ (mol %) 1.20 3.00 5.00 0.60 3.00 5.50 4.50 0.00 0.80 B₂O₃ (mol %) 4.00 4.00 10.00 10.00 5.00 2.00 2.00 2.00 2.00 MgO (mol %) 5.00 1.50 0.20 0.00 0.00 0.50 0.10 0.10 3.00 CaO (mol %) 1.28 4.00 4.48 0.00 5.00 2.00 1.90 3.06 4.14 SrO (mol %) 1.00 0.00 0.00 2.28 0.00 0.00 0.00 3.50 0.00 BaO (mol %) 1.00 0.48 0.00 2.30 3.18 4.18 5.18 1.00 0.00 TiO₂ (mol %) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.04 0.04 ZrO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 1.00 0.50 2.00 1.00 Li₂O (mol %) 8.50 9.00 14.50 4.00 16.00 15.00 13.00 0.00 0.00 Na₂O (mol %) 4.00 5.00 0.00 2.00 0.50 2.00 3.00 7.50 8.50 K₂O (mol %) 4.00 5.00 0.00 5.00 1.50 2.00 3.00 7.50 8.50 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.42 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.50 0.00 RO (mol %) 8.28 5.98 4.68 4.58 8.18 6.68 7.18 7.66 7.14 R₂O (mol %) 16.50 19.00 14.50 11.00 18.00 19.00 19.00 15.00 17.00 7Al₂O₃ + 3MgO (mol %) 23.4 25.5 35.6 4.2 21.0 40.0 31.8 0.3 14.6 7Al₂O₃ + 3MgO − 4Li₂O (mol %) −10.6 −10.5 −22.4 −11.8 −43.0 −20.0 −20.2 0.3 14.6 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 96.0 96.0 90.0 90.0 95.0 97.0 97.5 95.5 97.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 6.3 5.5 4.7 0.0 5.0 2.5 2.0 3.2 7.1 R₂O × MgO (mol %)² 82.5 28.5 2.9 0.0 0.0 9.5 1.9 1.5 51.0 Na₂O/R₂O 0.24 0.26 0.00 0.18 0.03 0.11 0.16 0.50 0.50 K₂O/R₂O 0.24 0.26 0.00 0.45 0.08 0.11 0.16 0.50 0.50 R₂O + B₂O₃ (mol %) 20.5 23.0 24.5 21.0 23.0 21.0 21.0 17.0 19.0 SiO₂ + Al₂O₃ (mol %) 71.2 71.0 70.8 74.4 68.8 71.3 71.3 72.4 72.8 FeO (mol %) — — — — — — — — — Fe-Redox (%) — — — — — — — — — Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 48% 51% 39% 55% 42% 43% 45% 43% 42% at 100 GHz d 2.50 2.48 2.47 2.53 2.55 2.53 2.57 2.59 2.48 α (×10⁻⁷/° C.) 84 91 58 66 81 84 90 96 100 E (GPa) 77 74 81 64 85 88 83 70 66 T_(g) (° C.) 422 416 396 430 406 448 425 520 514 T₂ (° C.) 1418 1381 1351 1507 1280 1399 1384 1419 1457 T₄ (° C.) 954 933 908 1017 820 907 901 998 1025 T_(L) (° C.) — — — — — — — — — T₄ − T_(L) (° C.) — — — — — — — — — Water resistance (mg) 0.30 0.25 0.31 0.24 0.22 0.40 0.36 0.30 0.41 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0429 0.0461 0.0351 0.0492 0.0374 0.0387 0.0407 0.0385 0.0378 Radio transmittance/t (thickness: 3.85 mm) 12.4 13.3 10.1 14.2 10.8 11.2 11.7 11.1 10.9 β-OH (mm⁻¹) — — — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — — — Maximum radio transmitted amount — — — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — — — of laminated glass (GHz) Ex. 243 Ex. 244 Ex. 245 Ex. 246 Ex. 247 Ex. 248 Ex. 249 Embodiment 10 10 10 10 10 10 10 SiO₂ (mol %) 70.34 70.34 70.34 67.74 72.41 74.01 75.00 Al₂O₃ (mol %) 1.20 1.20 1.20 0.60 0.60 1.00 0.30 B₂O₃ (mol %) 0.00 1.00 0.50 10.00 4.00 7.00 5.00 MgO (mol %) 4.30 2.50 3.00 0.50 4.00 1.00 1.00 CaO (mol %) 4.30 0.00 9.10 15.10 6.56 5.76 5.76 SrO (mol %) 0.00 2.00 0.00 0.00 0.00 0.00 0.00 BaO (mol %) 4.30 6.60 0.00 0.00 0.00 0.00 8.88 TiO₂ (mol %) 0.04 0.04 0.04 0.04 0.04 0.04 0.04 ZrO₂ (mol %) 0.50 1.30 0.80 0.00 0.00 0.00 0.00 Li₂O (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Na₂O (mol %) 7.50 10.00 3.00 3.00 6.05 7.95 2.00 K₂O (mol %) 7.50 5.00 12.00 3.00 6.32 3.22 2.00 Fe₂O₃ (mol %) 0.02 0.02 0.02 0.02 0.02 0.02 0.02 CeO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Cr2O3 (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 SnO₂ (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 PbO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 ZnO (mol %) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 RO (mol %) 12.90 11.10 12.10 15.60 10.56 6.76 15.64 R₂O (mol %) 15.00 15.00 15.00 6.00 12.37 11.17 4.00 7Al₂O₃ + 3MgO (mol %) 21.3 15.9 17.4 5.7 16.2 10.0 5.1 7Al₂O₃ + 3MgO − 4Li₂O (mol %) 21.3 15.9 17.4 5.7 16.2 10.0 5.1 SiO2 + Al₂O₃ + MgO + CaO + SrO + BaO + Li₂O + 99.5 97.7 98.7 90.0 96.0 93.0 95.0 Na₂O + K₂O + Fe₂O₃ + TiO₂ (mol %) MgO + CaO (mol %) 8.6 2.5 12.1 15.6 10.6 6.8 6.8 R₂O × MgO (mol %)² 64.5 37.5 45.0 3.0 49.5 11.2 4.0 Na₂O/R₂O 0.50 0.67 0.20 0.50 0.49 0.71 0.50 K₂O/R₂O 0.50 0.33 0.80 0.50 0.51 0.29 0.50 R₂O + B₂O₃ (mol %) 15.0 16.0 15.5 16.0 16.4 18.2 9.0 SiO₂ + Al₂O₃ (mol %) 71.5 71.5 71.5 68.3 73.0 75.0 75.3 FeO (mol %) — — — — — — — Fe-Redox (%) — — — — — — — Exponential approximation formula of relation — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 1 Exponential approximation formula of relation — — — — — — — between frequency and radio transmittance (as calculated as 18 mm thickness) constant 2 Radio transmittance with 18 mm thickness 36% 39% 30% 55% 43% 48% 50% at 100 GHz d 2.61 2.66 2.50 2.55 2.47 2.46 2.78 α (×10⁻⁷/° C.) 103 101 98 61 85 72 61 E (GPa) 70 70 63 69 68 66 70 T_(g) (° C.) 522 502 590 542 532 508 560 T₂ (° C.) 1458 1441 1474 1363 1488 1498 1572 T₄ (° C.) 1012 975 1070 1001 1047 1044 1066 T_(L) (° C.) — — — — — — — T₄ − T_(L) (° C.) — — — — — — — Water resistance (mg) 0.39 0.37 0.26 0.20 0.41 0.35 0.25 Visible light transmittance T_(VA) ◯ ◯ ◯ ◯ ◯ ◯ ◯ Visible light transmittance T_(VA) — — — — — — — measured value (%) Solar direct transmittance Te ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solar direct transmittance Te measured value (%) — — — — — — — Ultraviolet transmittance T_(uv) measured value (%) — — — — — — — A × radio transmittance (area: 0.0009 m²) 0.0327 0.0357 0.0270 0.0493 0.0386 0.043 0.0449 Radio transmittance/t (thickness: 3.85 mm) 9.4 10.3 7.8 14.2 11.1 12.4 13 β-OH (mm⁻¹) — — — — — — — Transmittance at wavelength 905 nm (%) — — — — — — — Transmittance at wavelength 1550 nm (%) — — — — — — — Maximum radio transmitted amount — — — — — — — at 75 to 90 GHz of laminated glass (dB) Frequency at maximum radio transmitted amount — — — — — — — of laminated glass (GHz)

[Studies on Calculation Model of Radio Transmittance]

Using the glass plate employed in Comparative Example 1 in Table 1, the difference between the transmittance of radio waves measured and the calculated model was confirmed. The measured value is one obtained by measurement by free space method using a 30 cm×30 cm glass plate. The calculation model of the free space method is a calculation model used in simulation by CST Microwave Studio 2016 electromagnetic simulator. The basic conditions of the simulation are as described in this specification. As a result of the studies, it was found that by adjusting the tanb value input in the calculation model with precision to three decimal places, the calculation model in a high frequency band (for example at least 50 GHz) was optimized, and more accurate fitting to measured values with respect to the glass plates having different thicknesses (for example 5 mm and 10 mm) was achieved.

Using the optimized calculation model, the radio transmittance or the approximate transmittance with respect to Comparative Example (conventional glass plate) was determined, and compared with those in Examples 1 to 249. As a result, the glass in each Example had a radio transmittance at a frequency of 100 GHz as calculated as 18 mm thickness of at least 20%, and was found to be superior to that in Comparative Example. Further, it was found that both radio transmittance x A where A is 0.009 m² and radio transmittance/thickness t at a thickness of 3.85 mm were more excellent than in Comparative Example.

[Comparison of Radio Transmittance]

FIGS. 2A to 2D are graphs illustrating the electric field strength ratios of glass plates with 18 mm thickness in Comparative Example 1 and Examples 1 to 20. The black curve represents the electric field strength ratio in Comparative Example, the black dotted line represents the radio transmittance calculated by the exponential approximation of curve of the electric field strength ratio in Comparative Example (approximation into a function [radio transmittance]=[constant 1]×e^([constant2]×[frequency]), that is, “exponential approximation of the relation between the frequency and the electric field strength ratio”). Likewise, gray curves respectively represent the electric field strength ratios in the respective Examples, and gray dotted lines represent ratio transmittances calculated by corresponding exponential approximation. The glass plates in Examples are found to generally have a high radio transmittance in GHz frequency band.

FIGS. 3A to 3D are graphs illustrating the approximate transmittances calculated at representative frequencies based on the exponential approximation formula obtained in FIGS. 2A to 2D. FIG. 3A corresponds to FIG. 2A, FIG. 3B to FIG. 2B, FIG. 3C to FIG. 2C, and FIG. 3D to FIG. 2D, and represent the approximate transmittances in Comparative Example 1 and Examples 1 to 20. It is found that in each Example, remarkably improved radio transmission characteristics than in Comparative Example are obtained.

Further, the glass plates in Examples 21 to 249 have any of the composition ranges as described in the above ten embodiments, and thereby have a high radio transmittance.

Further, the dielectric loss tanδ at a frequency of 35 GHz was at least 0.001 and at most 0.019 with respect to the glass in Examples 5 to 7 and 17 to 20, at least 0.001 and at most 0.013 with respect to the glass in Examples 2, 4, 8 to 10, 12, 14, 16 and 21 to 23, and at least 0.001 to at most 0.011 with respect to the glass in Examples 1, 3, 11, 13, 15 and 24.

From the results in Examples 3, 4, 11 and 25, the laminated glass in each Example has a higher radio transmittance than the laminated glass in Comparative Example.

INDUSTRIAL APPLICABILITY

The glass plate of the present invention is widely applicable as a window material of a building and a vehicle in which use of a radio-utilizing apparatus such as a mobile phone or radar is assumed.

Further, the glass plate of the present invention is suitable as a glass plate for a radio communication apparatus employing radio waves at a high frequency of at least 1.0 GHz.

This application is a continuation of PCT Application No. PCT/JP2018/017236 filed on Apr. 27, 2018, which is based upon and claims the benefit of priorities from Japanese Patent Application No. 2017-090141 filed on Apr. 28, 2017 and Japanese Patent Application No. 2017-140687 filed on Jul. 20, 2017. The contents of those applications are incorporated herein by reference in their entireties.

REFERENCE SYMBOLS

-   -   10: frame, 20: opening, 20: wave source, 40: measurement point. 

1: A glass plate having a radio transmittance of at least 20% at a frequency of 100 GHz as calculated as 18 mm thickness, wherein the glass plate contains, as represented by mol % based on oxides, the following components in the following contents: 55≤SiO₂≤75 1.44≤Al₂O₃≤9 0≤B₂O₃≤2 0≤MgO≤15 0≤CaO≤20 0≤SrO≤15 0≤BaO≤1 0.01≤Li₂O≤19.1 0≤Na₂O≤16 0.9≤K₂O≤16 0≤ZrO₂≤2 0.001≤Fe₂O₃≤5 0.001≤TiO₂≤5 0.91≤R₂O≤20 0≤RO≤20 85≤SiO₂+Al₂O₃+MgO+CaO+SrO+BaO+Li₂O+Na₂O+K₂O+Fe₂O₃+TiO₂≤100 10<7Al₂O₃+3MgO−4Li₂O≤66 0≤Na₂O/R₂O≤0.8 0≤PbO<0.001, 0≤ZnO≤3, wherein R₂O is a total content of alkali metal oxides, and RO is a total content of MgO, CaO, SrO, and BaO. 2: The glass plate according to claim 1, which has a radio transmittance of at least 25% at a frequency of 100 GHz as calculated as 18 mm thickness. 3: The glass plate according to claim 1, which has a radio transmittance of at most 84% at a frequency of 100 GHz as calculated as 18 mm thickness. 4: The glass plate according to claim 1, which satisfies, when plane waves at a frequency of 10 GHz at an electric field strength of 1 V/m are made to enter the glass plate having a thickness of 1.2λ from a wave source 2λ apart from an opening, a linear approximation of y>(0.0607×x), wherein y (V/m) is the electric field strength at a measurement point 10λ apart from the opening, and x is a value obtained by dividing the opening area S (mm²) by λ². 5: The glass plate according to claim 1, which satisfies an exponential approximation of y′>exp(−0.081×x′), wherein y′ is the approximate transmittance at a frequency of 100 GHz, and x′ is the thickness (mm) of the glass plate. 6: The glass plate according to claim 1, which satisfies an exponential approximation of the relation between the frequency x″ and the radio transmittance y″ at a frequency of from 6 to 20 GHz, as calculated as 18 mm thickness, approximated to a function y″=[constant 1]×e^([constant2]×x″), of y″>0.8619e^(−0.015x″). 7: The glass plate according to claim 1, which has an area of at least 900 mm². 8: The glass plate according to claim 1, which has a specific gravity of from 2.40 to 3.00, a Young's modulus of from 60 GPa to 100 GPa and an average coefficient of linear expansion from 50° C. to 350° C. of from 35×10⁻⁷ to 120×10⁻⁷. 9: The glass plate according to claim 1, which has a Na₂O elution amount in a water resistance test of from 0.001 mg to 0.6 mg. 10: The glass plate according to claim 1, wherein T₂ is at most 1,750° C., T₄ is at most 1,350° C., and T₄-T_(L) is at least −150° C., wherein T₂ is a temperature at which the glass viscosity becomes 10² (dPa·s), T₄ is a temperature at which the glass viscosity becomes 10⁴ (dPa·s), and T_(L). is the liquid phase temperature of the glass. 11: The glass plate according to claim 1, which has a glass transition point Tg of from 400° C. to 750° C. 12: The glass plate according to claim 1, which has a visible light transmittance T_(VA) of from 30 to 92% as calculated as 3.85 mm plate thickness. 13: The glass plate according to claim 1, which has a solar direct transmittance Te of from 35 to 91% as calculated as 3.85 mm plate thickness. 14-19. (canceled) 20: The glass plate according to claim 1, which contains, as represented by mol % based on oxides, the following components in the following contents: 60≤SiO₂≤73 0≤MgO≤10 0.5≤CaO≤18 0.5≤SrO≤12 1≤Li₂O≤15 1≤Na₂O≤15 1≤K₂O≤15 0.5≤ZrO₂≤1.8 5≤R₂O≤18 5≤RO≤19 11≤7Al₂O+3MgO−4Li₂O≤60 0.05≤Na₂O/R₂O≤0.6 0≤ZnO≤2. 21-23. (canceled) 24: The glass plate according to claim 1, wherein A×radio transmittance is from 0.0225 m^(2·)% to 8,400 m^(2·)%, wherein A is the area (m²) of the glass plate. 25: The glass plate according to claim 1, wherein radio transmittance/t is from 0.7%/mm to 84%/mm, wherein t is the thickness (mm) of the glass plate. 26: A window comprising the glass plate as defined in claim
 1. 27: The window according to claim 26, which is for an automobile or for a building. 28: A radio communication apparatus comprising the glass plate as defined in claim
 1. 